diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index dfbd1f82576e..2e5e5c31f2b8 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -801,7 +801,7 @@ jobs:
         include:
           # Only check typescript for latest version (to streamline CI)
           - node: 24
-            typescript: '3.8'
+            typescript: '5.0'
           # No need to test orchestrion for v18
           - node: 20
             use_orchestrion: 'true'
@@ -826,8 +826,8 @@ jobs:
           dependency_cache_key: ${{ needs.job_build.outputs.dependency_cache_key }}
 
       - name: Overwrite typescript version
-        if: matrix.typescript == '3.8'
-        run: node ./scripts/use-ts-3_8.js
+        if: matrix.typescript == '5.0'
+        run: node ./scripts/use-ts-5_0.js
         working-directory: dev-packages/node-integration-tests
 
       - name: Run integration tests
@@ -875,7 +875,7 @@ jobs:
         include:
           # Only check typescript for latest version (to streamline CI)
           - node: 24
-            typescript: '3.8'
+            typescript: '5.0'
     steps:
       - name: Check out current commit (${{ needs.job_get_metadata.outputs.commit_label }})
         uses: actions/checkout@v7
@@ -891,8 +891,8 @@ jobs:
           dependency_cache_key: ${{ needs.job_build.outputs.dependency_cache_key }}
 
       - name: Overwrite typescript version
-        if: matrix.typescript == '3.8'
-        run: node ./scripts/use-ts-3_8.js
+        if: matrix.typescript == '5.0'
+        run: node ./scripts/use-ts-5_0.js
         working-directory: dev-packages/node-core-integration-tests
 
       - name: Run integration tests
diff --git a/dev-packages/e2e-tests/test-applications/create-react-app/package.json b/dev-packages/e2e-tests/test-applications/create-react-app/package.json
index 30f745d60bc7..2c95f69f6ae3 100644
--- a/dev-packages/e2e-tests/test-applications/create-react-app/package.json
+++ b/dev-packages/e2e-tests/test-applications/create-react-app/package.json
@@ -19,7 +19,6 @@
     "eject": "react-scripts eject",
     "clean": "npx rimraf node_modules pnpm-lock.yaml",
     "test:build": "pnpm install && pnpm build",
-    "test:build-ts3.8": "pnpm install && pnpm add typescript@3.8 && pnpm build",
     "test:build-canary": "pnpm install && pnpm add react@canary react-dom@canary && pnpm build",
     "test:assert": "pnpm -v"
   },
@@ -43,13 +42,5 @@
   },
   "volta": {
     "extends": "../../package.json"
-  },
-  "sentryTest": {
-    "variants": [
-      {
-        "build-command": "pnpm test:build-ts3.8",
-        "label": "create-react-app (TS 3.8)"
-      }
-    ]
   }
 }
diff --git a/dev-packages/e2e-tests/test-applications/generic-ts3.8/index.ts b/dev-packages/e2e-tests/test-applications/generic-ts3.8/index.ts
deleted file mode 100644
index 9583861698e7..000000000000
--- a/dev-packages/e2e-tests/test-applications/generic-ts3.8/index.ts
+++ /dev/null
@@ -1,5 +0,0 @@
-import * as _SentryReplay from '@sentry/replay';
-import * as _SentryBrowser from '@sentry/browser';
-import * as _SentryCore from '@sentry/core';
-import * as _SentryNode from '@sentry/node';
-import * as _SentryWasm from '@sentry/wasm';
diff --git a/dev-packages/e2e-tests/test-applications/generic-ts3.8/package.json b/dev-packages/e2e-tests/test-applications/generic-ts3.8/package.json
deleted file mode 100644
index a06f32c7e44a..000000000000
--- a/dev-packages/e2e-tests/test-applications/generic-ts3.8/package.json
+++ /dev/null
@@ -1,34 +0,0 @@
-{
-  "name": "@sentry-internal/ts3.8-test",
-  "private": true,
-  "license": "MIT",
-  "scripts": {
-    "build:types": "pnpm run type-check",
-    "ts-version": "tsc --version",
-    "type-check": "tsc --project tsconfig.json",
-    "test:build": "pnpm install && pnpm run build:types",
-    "test:assert": "pnpm -v"
-  },
-  "devDependencies": {
-    "typescript": "3.8.3",
-    "@types/node": "^14.0.0"
-  },
-  "dependencies": {
-    "@sentry/browser": "file:../../packed/sentry-browser-packed.tgz",
-    "@sentry/core": "file:../../packed/sentry-core-packed.tgz",
-    "@sentry/node": "file:../../packed/sentry-node-packed.tgz",
-    "@sentry/replay": "file:../../packed/sentry-replay-packed.tgz",
-    "@sentry/wasm": "file:../../packed/sentry-wasm-packed.tgz"
-  },
-  "pnpm": {
-    "overrides": {
-      "@opentelemetry/api": "1.9.0",
-      "@opentelemetry/core": "<2.8.0",
-      "@opentelemetry/resources": "<2.8.0",
-      "@opentelemetry/sdk-trace-base": "<2.8.0"
-    }
-  },
-  "volta": {
-    "extends": "../../package.json"
-  }
-}
diff --git a/dev-packages/e2e-tests/test-applications/generic-ts3.8/tsconfig.json b/dev-packages/e2e-tests/test-applications/generic-ts3.8/tsconfig.json
deleted file mode 100644
index 46b70817524c..000000000000
--- a/dev-packages/e2e-tests/test-applications/generic-ts3.8/tsconfig.json
+++ /dev/null
@@ -1,11 +0,0 @@
-{
-  "include": ["index.ts"],
-  "compilerOptions": {
-    "lib": ["es2018", "DOM"],
-    "skipLibCheck": false,
-    "noEmit": true,
-    "types": ["node"],
-    "target": "es2018",
-    "moduleResolution": "node"
-  }
-}
diff --git a/dev-packages/e2e-tests/test-applications/react-17/package.json b/dev-packages/e2e-tests/test-applications/react-17/package.json
index 1982fffe7a53..6d4d3f8f4808 100644
--- a/dev-packages/e2e-tests/test-applications/react-17/package.json
+++ b/dev-packages/e2e-tests/test-applications/react-17/package.json
@@ -19,7 +19,6 @@
     "test": "playwright test",
     "clean": "npx rimraf node_modules pnpm-lock.yaml",
     "test:build": "pnpm install && pnpm build",
-    "test:build-ts3.8": "pnpm install && pnpm add typescript@3.8 && pnpm build",
     "test:build-canary": "pnpm install && pnpm add react@canary react-dom@canary && pnpm build",
     "test:assert": "pnpm test"
   },
diff --git a/dev-packages/e2e-tests/test-applications/react-router-6-descendant-routes/package.json b/dev-packages/e2e-tests/test-applications/react-router-6-descendant-routes/package.json
index 1457efba945e..afe9bc784a83 100644
--- a/dev-packages/e2e-tests/test-applications/react-router-6-descendant-routes/package.json
+++ b/dev-packages/e2e-tests/test-applications/react-router-6-descendant-routes/package.json
@@ -21,7 +21,6 @@
     "test": "playwright test",
     "clean": "npx rimraf node_modules pnpm-lock.yaml",
     "test:build": "pnpm install && npx playwright install && pnpm build",
-    "test:build-ts3.8": "pnpm install && pnpm add typescript@3.8 && npx playwright install && pnpm build",
     "test:build-canary": "pnpm install && pnpm add react@canary react-dom@canary && npx playwright install && pnpm build",
     "test:assert": "pnpm test"
   },
diff --git a/dev-packages/e2e-tests/test-applications/react-router-6-use-routes/package.json b/dev-packages/e2e-tests/test-applications/react-router-6-use-routes/package.json
index 128c4967554c..43319e53e145 100644
--- a/dev-packages/e2e-tests/test-applications/react-router-6-use-routes/package.json
+++ b/dev-packages/e2e-tests/test-applications/react-router-6-use-routes/package.json
@@ -18,7 +18,6 @@
     "test": "playwright test",
     "clean": "npx rimraf node_modules pnpm-lock.yaml",
     "test:build": "pnpm install && pnpm build",
-    "test:build-ts3.8": "pnpm install && pnpm add typescript@3.8 && pnpm build",
     "test:build-canary": "pnpm install && pnpm add react@canary react-dom@canary && pnpm build",
     "test:assert": "pnpm test"
   },
diff --git a/dev-packages/e2e-tests/test-applications/react-router-6/package.json b/dev-packages/e2e-tests/test-applications/react-router-6/package.json
index 2d84c95d58f1..95caba4c8d2f 100644
--- a/dev-packages/e2e-tests/test-applications/react-router-6/package.json
+++ b/dev-packages/e2e-tests/test-applications/react-router-6/package.json
@@ -21,7 +21,6 @@
     "test": "playwright test",
     "clean": "npx rimraf node_modules pnpm-lock.yaml",
     "test:build": "pnpm install && pnpm build",
-    "test:build-ts3.8": "pnpm install && pnpm add typescript@3.8 && pnpm build",
     "test:build-canary": "pnpm install && pnpm add react@canary react-dom@canary && pnpm build",
     "test:assert": "pnpm test"
   },
@@ -51,13 +50,5 @@
   },
   "volta": {
     "extends": "../../package.json"
-  },
-  "sentryTest": {
-    "variants": [
-      {
-        "build-command": "pnpm test:build-ts3.8",
-        "label": "react-router-6 (TS 3.8)"
-      }
-    ]
   }
 }
diff --git a/dev-packages/e2e-tests/test-applications/react-router-7-cross-usage/package.json b/dev-packages/e2e-tests/test-applications/react-router-7-cross-usage/package.json
index 586fbccee112..2045f51dced8 100644
--- a/dev-packages/e2e-tests/test-applications/react-router-7-cross-usage/package.json
+++ b/dev-packages/e2e-tests/test-applications/react-router-7-cross-usage/package.json
@@ -19,7 +19,6 @@
     "test": "playwright test",
     "clean": "npx rimraf node_modules pnpm-lock.yaml",
     "test:build": "pnpm install && npx playwright install && pnpm build",
-    "test:build-ts3.8": "pnpm install && pnpm add typescript@3.8 && npx playwright install && pnpm build",
     "test:build-canary": "pnpm install && pnpm add react@canary react-dom@canary && npx playwright install && pnpm build",
     "test:assert": "pnpm test"
   },
diff --git a/dev-packages/e2e-tests/test-applications/react-router-7-lazy-routes/package.json b/dev-packages/e2e-tests/test-applications/react-router-7-lazy-routes/package.json
index 9e649c11afbe..00fa2865ff5c 100644
--- a/dev-packages/e2e-tests/test-applications/react-router-7-lazy-routes/package.json
+++ b/dev-packages/e2e-tests/test-applications/react-router-7-lazy-routes/package.json
@@ -19,7 +19,6 @@
     "test": "playwright test",
     "clean": "npx rimraf node_modules pnpm-lock.yaml",
     "test:build": "pnpm install && npx playwright install && pnpm build",
-    "test:build-ts3.8": "pnpm install && pnpm add typescript@3.8 && npx playwright install && pnpm build",
     "test:build-canary": "pnpm install && pnpm add react@canary react-dom@canary && npx playwright install && pnpm build",
     "test:assert": "pnpm test"
   },
diff --git a/dev-packages/e2e-tests/test-applications/react-router-7-spa-streaming/package.json b/dev-packages/e2e-tests/test-applications/react-router-7-spa-streaming/package.json
index 4fddbfa60945..1b6c3562674f 100644
--- a/dev-packages/e2e-tests/test-applications/react-router-7-spa-streaming/package.json
+++ b/dev-packages/e2e-tests/test-applications/react-router-7-spa-streaming/package.json
@@ -24,7 +24,6 @@
     "test": "playwright test",
     "clean": "npx rimraf node_modules pnpm-lock.yaml",
     "test:build": "pnpm install && pnpm build",
-    "test:build-ts3.8": "pnpm install && pnpm add typescript@3.8 && pnpm build",
     "test:build-canary": "pnpm install && pnpm add react@canary react-dom@canary && pnpm build",
     "test:assert": "pnpm test"
   },
@@ -48,18 +47,5 @@
   },
   "volta": {
     "extends": "../../package.json"
-  },
-  "sentryTest": {
-    "variants": [
-      {
-        "build-command": "pnpm test:build-ts3.8",
-        "label": "react-router-7-spa-streaming (TS 3.8)"
-      }
-    ]
-  },
-  "pnpm": {
-    "overrides": {
-      "esbuild": "0.24.0"
-    }
   }
 }
diff --git a/dev-packages/e2e-tests/test-applications/react-router-7-spa/package.json b/dev-packages/e2e-tests/test-applications/react-router-7-spa/package.json
index eee79f453d56..faf27549ef82 100644
--- a/dev-packages/e2e-tests/test-applications/react-router-7-spa/package.json
+++ b/dev-packages/e2e-tests/test-applications/react-router-7-spa/package.json
@@ -24,7 +24,6 @@
     "test": "playwright test",
     "clean": "npx rimraf node_modules pnpm-lock.yaml",
     "test:build": "pnpm install && pnpm build",
-    "test:build-ts3.8": "pnpm install && pnpm add typescript@3.8 && pnpm build",
     "test:build-canary": "pnpm install && pnpm add react@canary react-dom@canary && pnpm build",
     "test:assert": "pnpm test"
   },
@@ -48,18 +47,5 @@
   },
   "volta": {
     "extends": "../../package.json"
-  },
-  "sentryTest": {
-    "variants": [
-      {
-        "build-command": "pnpm test:build-ts3.8",
-        "label": "react-router-7-spa (TS 3.8)"
-      }
-    ]
-  },
-  "pnpm": {
-    "overrides": {
-      "esbuild": "0.24.0"
-    }
   }
 }
diff --git a/dev-packages/e2e-tests/test-applications/react-router-8-cross-usage/package.json b/dev-packages/e2e-tests/test-applications/react-router-8-cross-usage/package.json
index ae35c97e950d..a1bbfc65d5c6 100644
--- a/dev-packages/e2e-tests/test-applications/react-router-8-cross-usage/package.json
+++ b/dev-packages/e2e-tests/test-applications/react-router-8-cross-usage/package.json
@@ -19,7 +19,6 @@
     "test": "playwright test",
     "clean": "npx rimraf node_modules pnpm-lock.yaml",
     "test:build": "pnpm install && npx playwright install && pnpm build",
-    "test:build-ts3.8": "pnpm install && pnpm add typescript@3.8 && npx playwright install && pnpm build",
     "test:build-canary": "pnpm install && pnpm add react@canary react-dom@canary && npx playwright install && pnpm build",
     "test:assert": "pnpm test"
   },
diff --git a/dev-packages/e2e-tests/test-applications/react-router-8-spa/package.json b/dev-packages/e2e-tests/test-applications/react-router-8-spa/package.json
index 67b016407d0c..84af76a61e60 100644
--- a/dev-packages/e2e-tests/test-applications/react-router-8-spa/package.json
+++ b/dev-packages/e2e-tests/test-applications/react-router-8-spa/package.json
@@ -24,7 +24,6 @@
     "test": "playwright test",
     "clean": "npx rimraf node_modules pnpm-lock.yaml",
     "test:build": "pnpm install && pnpm build",
-    "test:build-ts3.8": "pnpm install && pnpm add typescript@3.8 && pnpm build",
     "test:build-canary": "pnpm install && pnpm add react@canary react-dom@canary && pnpm build",
     "test:assert": "pnpm test"
   },
@@ -48,13 +47,5 @@
   },
   "volta": {
     "extends": "../../package.json"
-  },
-  "sentryTest": {
-    "variants": [
-      {
-        "build-command": "pnpm test:build-ts3.8",
-        "label": "react-router-8-spa (TS 3.8)"
-      }
-    ]
   }
 }
diff --git a/dev-packages/e2e-tests/test-applications/react-send-to-sentry/package.json b/dev-packages/e2e-tests/test-applications/react-send-to-sentry/package.json
index b5958cefd6f7..6c32218f62b4 100644
--- a/dev-packages/e2e-tests/test-applications/react-send-to-sentry/package.json
+++ b/dev-packages/e2e-tests/test-applications/react-send-to-sentry/package.json
@@ -19,7 +19,6 @@
     "test": "playwright test",
     "clean": "npx rimraf node_modules pnpm-lock.yaml",
     "test:build": "pnpm install && pnpm build",
-    "test:build-ts3.8": "pnpm install && pnpm add typescript@3.8 && pnpm build",
     "test:build-canary": "pnpm install && pnpm add react@canary react-dom@canary && pnpm build",
     "test:assert": "pnpm test"
   },
diff --git a/dev-packages/node-core-integration-tests/scripts/use-ts-3_8.js b/dev-packages/node-core-integration-tests/scripts/use-ts-3_8.js
deleted file mode 100644
index e687786ec5c5..000000000000
--- a/dev-packages/node-core-integration-tests/scripts/use-ts-3_8.js
+++ /dev/null
@@ -1,44 +0,0 @@
-/* eslint-disable no-console */
-const { execSync } = require('child_process');
-const { join } = require('path');
-const { readFileSync, writeFileSync } = require('fs');
-
-const cwd = join(__dirname, '../../..');
-
-// Newer versions of the Express types use syntax that isn't supported by TypeScript 3.8.
-// We'll pin to the last version of those types that are compatible.
-console.log('Pinning Express types to old versions...');
-
-const packageJsonPath = join(cwd, 'package.json');
-const packageJson = JSON.parse(readFileSync(packageJsonPath, 'utf8'));
-
-if (!packageJson.resolutions) packageJson.resolutions = {};
-packageJson.resolutions['@types/express'] = '4.17.13';
-packageJson.resolutions['@types/express-serve-static-core'] = '4.17.30';
-
-writeFileSync(packageJsonPath, JSON.stringify(packageJson, null, 2));
-
-const tsVersion = '3.8';
-
-console.log(`Installing typescript@${tsVersion}, and @types/node@14...`);
-
-execSync(`yarn add --dev --ignore-workspace-root-check typescript@${tsVersion} @types/node@^14`, {
-  stdio: 'inherit',
-  cwd,
-});
-
-console.log('Removing unsupported tsconfig options...');
-
-const baseTscConfigPath = join(cwd, 'packages/typescript/tsconfig.json');
-
-const tsConfig = require(baseTscConfigPath);
-
-// TS 3.8 fails build when it encounters a config option it does not understand, so we remove it :(
-delete tsConfig.compilerOptions.noUncheckedIndexedAccess;
-
-// TS 3.8 doesn't support "bundler" moduleResolution (introduced in TS 5.0)
-if (tsConfig.compilerOptions.moduleResolution === 'bundler') {
-  tsConfig.compilerOptions.moduleResolution = 'node';
-}
-
-writeFileSync(baseTscConfigPath, JSON.stringify(tsConfig, null, 2));
diff --git a/dev-packages/node-core-integration-tests/scripts/use-ts-5_0.js b/dev-packages/node-core-integration-tests/scripts/use-ts-5_0.js
new file mode 100644
index 000000000000..862c82a6a7f4
--- /dev/null
+++ b/dev-packages/node-core-integration-tests/scripts/use-ts-5_0.js
@@ -0,0 +1,16 @@
+/* eslint-disable no-console */
+const { execSync } = require('child_process');
+const { join } = require('path');
+
+const cwd = join(__dirname, '../../..');
+
+const tsVersion = '5.0.4';
+
+console.log(`Installing typescript@${tsVersion}, and @types/node@18...`);
+
+execSync(`yarn add --dev --ignore-workspace-root-check typescript@${tsVersion} @types/node@^18`, {
+  stdio: 'inherit',
+  cwd,
+});
+
+console.log('TypeScript version updated successfully.');
diff --git a/dev-packages/node-core-integration-tests/utils/runner.ts b/dev-packages/node-core-integration-tests/utils/runner.ts
index 26868b59ef6b..3e7a28632f15 100644
--- a/dev-packages/node-core-integration-tests/utils/runner.ts
+++ b/dev-packages/node-core-integration-tests/utils/runner.ts
@@ -445,8 +445,6 @@ export function createRunner(...paths: string[]) {
         }
       }
 
-      // We need to properly define & pass these types around for TS 3.8,
-      // which otherwise fails to infer these correctly :(
       type ServerStartup = [number | undefined, (() => void) | undefined];
       type DockerStartup = VoidFunction | undefined;
 
diff --git a/dev-packages/node-integration-tests/scripts/use-ts-3_8.js b/dev-packages/node-integration-tests/scripts/use-ts-3_8.js
deleted file mode 100644
index e687786ec5c5..000000000000
--- a/dev-packages/node-integration-tests/scripts/use-ts-3_8.js
+++ /dev/null
@@ -1,44 +0,0 @@
-/* eslint-disable no-console */
-const { execSync } = require('child_process');
-const { join } = require('path');
-const { readFileSync, writeFileSync } = require('fs');
-
-const cwd = join(__dirname, '../../..');
-
-// Newer versions of the Express types use syntax that isn't supported by TypeScript 3.8.
-// We'll pin to the last version of those types that are compatible.
-console.log('Pinning Express types to old versions...');
-
-const packageJsonPath = join(cwd, 'package.json');
-const packageJson = JSON.parse(readFileSync(packageJsonPath, 'utf8'));
-
-if (!packageJson.resolutions) packageJson.resolutions = {};
-packageJson.resolutions['@types/express'] = '4.17.13';
-packageJson.resolutions['@types/express-serve-static-core'] = '4.17.30';
-
-writeFileSync(packageJsonPath, JSON.stringify(packageJson, null, 2));
-
-const tsVersion = '3.8';
-
-console.log(`Installing typescript@${tsVersion}, and @types/node@14...`);
-
-execSync(`yarn add --dev --ignore-workspace-root-check typescript@${tsVersion} @types/node@^14`, {
-  stdio: 'inherit',
-  cwd,
-});
-
-console.log('Removing unsupported tsconfig options...');
-
-const baseTscConfigPath = join(cwd, 'packages/typescript/tsconfig.json');
-
-const tsConfig = require(baseTscConfigPath);
-
-// TS 3.8 fails build when it encounters a config option it does not understand, so we remove it :(
-delete tsConfig.compilerOptions.noUncheckedIndexedAccess;
-
-// TS 3.8 doesn't support "bundler" moduleResolution (introduced in TS 5.0)
-if (tsConfig.compilerOptions.moduleResolution === 'bundler') {
-  tsConfig.compilerOptions.moduleResolution = 'node';
-}
-
-writeFileSync(baseTscConfigPath, JSON.stringify(tsConfig, null, 2));
diff --git a/dev-packages/node-integration-tests/scripts/use-ts-5_0.js b/dev-packages/node-integration-tests/scripts/use-ts-5_0.js
new file mode 100644
index 000000000000..862c82a6a7f4
--- /dev/null
+++ b/dev-packages/node-integration-tests/scripts/use-ts-5_0.js
@@ -0,0 +1,16 @@
+/* eslint-disable no-console */
+const { execSync } = require('child_process');
+const { join } = require('path');
+
+const cwd = join(__dirname, '../../..');
+
+const tsVersion = '5.0.4';
+
+console.log(`Installing typescript@${tsVersion}, and @types/node@18...`);
+
+execSync(`yarn add --dev --ignore-workspace-root-check typescript@${tsVersion} @types/node@^18`, {
+  stdio: 'inherit',
+  cwd,
+});
+
+console.log('TypeScript version updated successfully.');
diff --git a/dev-packages/node-integration-tests/utils/runner/createRunner.ts b/dev-packages/node-integration-tests/utils/runner/createRunner.ts
index 069de2c26249..2b7cbd2b0c84 100644
--- a/dev-packages/node-integration-tests/utils/runner/createRunner.ts
+++ b/dev-packages/node-integration-tests/utils/runner/createRunner.ts
@@ -386,8 +386,6 @@ export function createRunner(...paths: string[]) {
         }
       }
 
-      // We need to properly define & pass these types around for TS 3.8,
-      // which otherwise fails to infer these correctly :(
       type ServerStartup = [number | undefined, (() => void) | undefined];
 
       const serverStartup: Promise<ServerStartup> = withSentryServer
diff --git a/dev-packages/rollup-utils/npmHelpers.mjs b/dev-packages/rollup-utils/npmHelpers.mjs
index 0014616f8071..eb6bd0521d11 100644
--- a/dev-packages/rollup-utils/npmHelpers.mjs
+++ b/dev-packages/rollup-utils/npmHelpers.mjs
@@ -81,9 +81,9 @@ export function makeBaseNPMConfig(options = {}) {
       // don't add `"use strict"` to the top of cjs files
       strict: false,
 
-      // do TS-3.8-style exports
+      // Use simple exports format:
       //     exports.dogs = are.great
-      // rather than TS-3.9-style exports
+      // rather than Object.defineProperty style exports:
       //     Object.defineProperty(exports, 'dogs', {
       //       enumerable: true,
       //       get: () => are.great,
diff --git a/dev-packages/test-utils/package.json b/dev-packages/test-utils/package.json
index 02590211af37..a94734156b42 100644
--- a/dev-packages/test-utils/package.json
+++ b/dev-packages/test-utils/package.json
@@ -10,8 +10,7 @@
   "files": [
     "cjs",
     "esm",
-    "types",
-    "types-ts3.8"
+    "types"
   ],
   "exports": {
     "./package.json": "./package.json",
diff --git a/nx.json b/nx.json
index d869745b42ee..7172fd762629 100644
--- a/nx.json
+++ b/nx.json
@@ -40,12 +40,7 @@
     "build:types": {
       "inputs": ["production", "^production"],
       "dependsOn": ["^build:types"],
-      "outputs": [
-        "{projectRoot}/build/types",
-        "{projectRoot}/build/types-ts3.8",
-        "{projectRoot}/build/npm/types",
-        "{projectRoot}/build/npm/types-ts3.8"
-      ],
+      "outputs": ["{projectRoot}/build/types", "{projectRoot}/build/npm/types"],
       "cache": true
     },
     "lint": {
diff --git a/package.json b/package.json
index 70e127288d58..254cc0290dac 100644
--- a/package.json
+++ b/package.json
@@ -129,7 +129,6 @@
     "@types/node": "^18.19.1",
     "@vitest/coverage-v8": "^3.2.4",
     "deepmerge": "^4.2.2",
-    "downlevel-dts": "~0.11.0",
     "es-check": "^7.2.1",
     "esbuild": "^0.28.1",
     "jsdom": "^21.1.2",
diff --git a/packages/aws-serverless/package.json b/packages/aws-serverless/package.json
index 5924038d5867..48d139cc6b22 100644
--- a/packages/aws-serverless/package.json
+++ b/packages/aws-serverless/package.json
@@ -58,13 +58,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/npm/types/index.d.ts": [
-        "build/npm/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -88,9 +81,7 @@
     "build:dev": "run-p build:transpile build:types",
     "build:transpile": "run-s build:transpile:npm build:extension",
     "build:transpile:npm": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/npm/types build/npm/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "yarn build:watch",
     "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
diff --git a/packages/browser-utils/package.json b/packages/browser-utils/package.json
index 2f76ecbcc107..c4b87dacb07a 100644
--- a/packages/browser-utils/package.json
+++ b/packages/browser-utils/package.json
@@ -29,13 +29,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/types/index.d.ts": [
-        "build/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -47,9 +40,7 @@
     "build": "run-p build:transpile build:types",
     "build:dev": "yarn build",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "run-p build:transpile:watch",
     "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
diff --git a/packages/browser/package.json b/packages/browser/package.json
index 524ca585df58..0c8e7fff202d 100644
--- a/packages/browser/package.json
+++ b/packages/browser/package.json
@@ -34,13 +34,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/npm/types/index.d.ts": [
-        "build/npm/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -61,9 +54,7 @@
     "build:dev": "run-p build:transpile build:types",
     "build:bundle": "rollup -c rollup.bundle.config.mjs",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/npm/types build/npm/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch build:bundle:watch",
     "build:dev:watch": "run-p build:transpile:watch",
     "build:bundle:watch": "rollup -c rollup.bundle.config.mjs --watch",
diff --git a/packages/bun/package.json b/packages/bun/package.json
index 16f6fcc73c05..d162471f7024 100644
--- a/packages/bun/package.json
+++ b/packages/bun/package.json
@@ -38,13 +38,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/types/index.d.ts": [
-        "build/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -61,9 +54,7 @@
     "build": "run-p build:transpile build:types",
     "build:dev": "yarn build",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "yarn build:watch",
     "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
diff --git a/packages/bundler-plugins/package.json b/packages/bundler-plugins/package.json
index 6a3f3ac10a77..748f693277de 100644
--- a/packages/bundler-plugins/package.json
+++ b/packages/bundler-plugins/package.json
@@ -71,9 +71,7 @@
     "build:dev": "yarn build",
     "build:version": "node -p \"'export const LIB_VERSION = ' + JSON.stringify(require('./package.json').version) + ';'\" > src/core/version.ts",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "yarn build:watch",
     "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
diff --git a/packages/cloudflare/package.json b/packages/cloudflare/package.json
index ff5e95ea9504..8f680202c46f 100644
--- a/packages/cloudflare/package.json
+++ b/packages/cloudflare/package.json
@@ -48,13 +48,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/types/index.d.ts": [
-        "build/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -81,9 +74,7 @@
     "build": "run-p build:transpile build:types",
     "build:dev": "yarn build",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "yarn build:watch",
     "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
diff --git a/packages/core/browser.d.ts b/packages/core/browser.d.ts
index 752c159c689d..e60b7f9f51fe 100644
--- a/packages/core/browser.d.ts
+++ b/packages/core/browser.d.ts
@@ -1,4 +1,3 @@
 // This file is a compatibility shim for TypeScript compilers that do not
 // support the package.json `exports` field for resolving subpath exports.
-// Note: `typesVersions` in package.json may redirect this to the downleveled variant.
 export * from './build/types/browser';
diff --git a/packages/core/package.json b/packages/core/package.json
index db57bf270f69..34ada929a888 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -64,19 +64,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/types/index.d.ts": [
-        "build/types-ts3.8/index.d.ts"
-      ],
-      "browser": [
-        "build/types-ts3.8/browser.d.ts"
-      ],
-      "server": [
-        "build/types-ts3.8/server.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -84,9 +71,7 @@
     "build": "run-p build:transpile build:types",
     "build:dev": "yarn build",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "yarn build:watch",
     "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
diff --git a/packages/core/server.d.ts b/packages/core/server.d.ts
index 7be138fe726e..a76408a89962 100644
--- a/packages/core/server.d.ts
+++ b/packages/core/server.d.ts
@@ -1,4 +1,3 @@
 // This file is a compatibility shim for TypeScript compilers that do not
 // support the package.json `exports` field for resolving subpath exports.
-// Note: `typesVersions` in package.json may redirect this to the downleveled variant.
 export * from './build/types/server';
diff --git a/packages/core/src/utils/handleCallbackErrors.ts b/packages/core/src/utils/handleCallbackErrors.ts
index 4fa0b036c101..69ad50c9bda1 100644
--- a/packages/core/src/utils/handleCallbackErrors.ts
+++ b/packages/core/src/utils/handleCallbackErrors.ts
@@ -1,19 +1,8 @@
 import { chainAndCopyPromiseLike } from '../utils/chain-and-copy-promiselike';
 import { isThenable } from '../utils/is';
 
-/* eslint-disable */
-// Vendor "Awaited" in to be TS 3.8 compatible
-type AwaitedPromise<T> = T extends null | undefined
-  ? T // special case for `null | undefined` when not in `--strictNullChecks` mode
-  : T extends object & { then(onfulfilled: infer F, ...args: infer _): any } // `await` only unwraps object types with a callable `then`. Non-object types are not unwrapped
-    ? F extends (value: infer V, ...args: infer _) => any // if the argument to `then` is callable, extracts the first argument
-      ? V // normally this would recursively unwrap, but this is not possible in TS3.8
-      : never // the argument to `then` was not callable
-    : T; // non-object or non-thenable
-/* eslint-enable */
-
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
-export function handleCallbackErrors<Fn extends () => Promise<any>, PromiseValue = AwaitedPromise<ReturnType<Fn>>>(
+export function handleCallbackErrors<Fn extends () => Promise<any>, PromiseValue = Awaited<ReturnType<Fn>>>(
   fn: Fn,
   onError: (error: unknown) => void,
   onFinally?: () => void,
@@ -45,7 +34,7 @@ export function handleCallbackErrors<
   fn: Fn,
   onError: (error: unknown) => void,
   onFinally: () => void = () => {},
-  onSuccess: (result: ValueType | AwaitedPromise<ValueType>) => void = () => {},
+  onSuccess: (result: ValueType | Awaited<ValueType>) => void = () => {},
 ): ValueType {
   let maybePromiseResult: ReturnType<Fn>;
   try {
@@ -74,7 +63,7 @@ function maybeHandlePromiseRejection<MaybePromise>(
   value: MaybePromise,
   onError: (error: unknown) => void,
   onFinally: () => void,
-  onSuccess: (result: MaybePromise | AwaitedPromise<MaybePromise>) => void,
+  onSuccess: (result: MaybePromise | Awaited<MaybePromise>) => void,
 ): MaybePromise {
   if (isThenable(value)) {
     return chainAndCopyPromiseLike(
diff --git a/packages/effect/package.json b/packages/effect/package.json
index fc0eb66a2333..c2d0ff791a12 100644
--- a/packages/effect/package.json
+++ b/packages/effect/package.json
@@ -40,19 +40,6 @@
       "require": "./build/cjs/index.client.js"
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/types/index.types.d.ts": [
-        "build/types-ts3.8/index.types.d.ts"
-      ],
-      "build/types/index.server.d.ts": [
-        "build/types-ts3.8/index.server.d.ts"
-      ],
-      "build/types/index.client.d.ts": [
-        "build/types-ts3.8/index.client.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -77,9 +64,7 @@
     "build": "run-p build:transpile build:types",
     "build:dev": "yarn build",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "yarn build:watch",
     "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
diff --git a/packages/elysia/package.json b/packages/elysia/package.json
index 05f6408b9c51..8cbd5d26d9bb 100644
--- a/packages/elysia/package.json
+++ b/packages/elysia/package.json
@@ -28,13 +28,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/types/index.d.ts": [
-        "build/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -58,9 +51,7 @@
     "build": "run-p build:transpile build:types",
     "build:dev": "yarn build",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "yarn build:watch",
     "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
diff --git a/packages/feedback/package.json b/packages/feedback/package.json
index 3221159ded4f..cac1a857bf80 100644
--- a/packages/feedback/package.json
+++ b/packages/feedback/package.json
@@ -29,13 +29,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/npm/types/index.d.ts": [
-        "build/npm/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -50,9 +43,7 @@
     "build:transpile": "rollup -c rollup.npm.config.mjs",
     "build:bundle": "rollup -c rollup.bundle.config.mjs",
     "build:dev": "run-p build:transpile build:types",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/npm/types build/npm/types-ts3.8 --to ts3.8 && yarn node ./scripts/shim-preact-export.js",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch build:bundle:watch",
     "build:dev:watch": "run-p build:transpile:watch",
     "build:transpile:watch": "yarn build:transpile --watch",
diff --git a/packages/feedback/scripts/shim-preact-export.js b/packages/feedback/scripts/shim-preact-export.js
deleted file mode 100644
index bd74e4da0a05..000000000000
--- a/packages/feedback/scripts/shim-preact-export.js
+++ /dev/null
@@ -1,75 +0,0 @@
-// preact does not support more modern TypeScript versions, which breaks our users that depend on older
-// TypeScript versions. To fix this, we shim the types from preact to be any and remove the dependency on preact
-// for types directly. This script is meant to be run after the build/npm/types-ts3.8 directory is created.
-
-// Path: build/npm/types-ts3.8/global.d.ts
-
-const fs = require('fs');
-const path = require('path');
-
-/**
- * This regex looks for preact imports we can replace and shim out.
- *
- * Example:
- * import { ComponentChildren, VNode } from 'preact';
- */
-const preactImportRegex = /import\s*{\s*([\w\s,]+)\s*}\s*from\s*'preact'\s*;?/;
-
-function walk(dir) {
-  const files = fs.readdirSync(dir);
-  files.forEach(file => {
-    const filePath = path.join(dir, file);
-    const stat = fs.lstatSync(filePath);
-    if (stat.isDirectory()) {
-      walk(filePath);
-    } else {
-      if (filePath.endsWith('.d.ts')) {
-        const content = fs.readFileSync(filePath, 'utf8');
-        const capture = preactImportRegex.exec(content);
-        if (capture) {
-          const groups = capture[1].split(',').map(s => s.trim());
-
-          // This generates a shim snippet to replace the type imports from preact
-          // It generates a snippet based on the capture groups of preactImportRegex.
-          //
-          // Example:
-          //
-          // import type { ComponentChildren, VNode } from 'preact';
-          // becomes
-          // type ComponentChildren: any;
-          // type VNode: any;
-          const snippet = groups.reduce((acc, curr) => {
-            const searchableValue = curr.includes(' as ') ? curr.split(' as ')[1] : curr;
-
-            // look to see if imported as value, then we have to use declare const
-            if (content.includes(`typeof ${searchableValue}`)) {
-              return `${acc}declare const ${searchableValue}: any;\n`;
-            }
-
-            // look to see if generic type like Foo<T>
-            if (content.includes(`${searchableValue}<`)) {
-              return `${acc}type ${searchableValue}<T> = any;\n`;
-            }
-
-            // otherwise we can just leave as type
-            return `${acc}type ${searchableValue} = any;\n`;
-          }, '');
-
-          // we then can remove the import from preact
-          const newContent = content.replace(preactImportRegex, '// replaced import from preact');
-
-          // and write the new content to the file
-          fs.writeFileSync(filePath, snippet + newContent, 'utf8');
-        }
-      }
-    }
-  });
-}
-
-function run() {
-  // recurse through build/npm/types-ts3.8 directory
-  const dir = path.join('build', 'npm', 'types-ts3.8');
-  walk(dir);
-}
-
-run();
diff --git a/packages/gatsby/package.json b/packages/gatsby/package.json
index e060f16bb0d4..af875493566a 100644
--- a/packages/gatsby/package.json
+++ b/packages/gatsby/package.json
@@ -34,13 +34,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/types/index.d.ts": [
-        "build/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -65,9 +58,7 @@
     "build:plugin": "tsc -p tsconfig.plugin.json",
     "build:transpile": "run-p build:rollup build:plugin",
     "build:rollup": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "yarn build:watch",
     "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
diff --git a/packages/google-cloud-serverless/package.json b/packages/google-cloud-serverless/package.json
index b1db975e5b04..7fc963031fde 100644
--- a/packages/google-cloud-serverless/package.json
+++ b/packages/google-cloud-serverless/package.json
@@ -37,13 +37,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/types/index.d.ts": [
-        "build/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -71,9 +64,7 @@
     "build": "run-p build:transpile build:types",
     "build:dev": "yarn build",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "yarn build:watch",
     "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
diff --git a/packages/hono/package.json b/packages/hono/package.json
index a6696e675809..909168514621 100644
--- a/packages/hono/package.json
+++ b/packages/hono/package.json
@@ -68,25 +68,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/types/index.d.ts": [
-        "build/types-ts3.8/index.d.ts"
-      ],
-      "build/types/index.cloudflare.d.ts": [
-        "build/types-ts3.8/index.cloudflare.d.ts"
-      ],
-      "build/types/index.node.d.ts": [
-        "build/types-ts3.8/index.node.d.ts"
-      ],
-      "build/types/index.bun.d.ts": [
-        "build/types-ts3.8/index.bun.d.ts"
-      ],
-      "build/types/index.deno.d.ts": [
-        "build/types-ts3.8/index.deno.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -133,9 +114,7 @@
     "build": "run-p build:transpile build:types",
     "build:dev": "yarn build",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "yarn build:watch",
     "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
diff --git a/packages/integration-shims/package.json b/packages/integration-shims/package.json
index 997a4914196e..93cf4715db06 100644
--- a/packages/integration-shims/package.json
+++ b/packages/integration-shims/package.json
@@ -21,21 +21,12 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/types/index.d.ts": [
-        "build/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "sideEffects": false,
   "private": true,
   "scripts": {
     "build": "run-p build:transpile build:types",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:dev": "yarn build",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "run-p build:watch",
diff --git a/packages/nestjs/package.json b/packages/nestjs/package.json
index ad637e515e34..a8a5d8385f16 100644
--- a/packages/nestjs/package.json
+++ b/packages/nestjs/package.json
@@ -95,7 +95,6 @@
         ],
         "outputs": [
           "{projectRoot}/build/types",
-          "{projectRoot}/build/types-ts3.8",
           "{projectRoot}/*.d.ts"
         ],
         "cache": true
diff --git a/packages/nextjs/package.json b/packages/nextjs/package.json
index 3c1e65034872..7502ad28052b 100644
--- a/packages/nextjs/package.json
+++ b/packages/nextjs/package.json
@@ -65,13 +65,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/npm/types/index.d.ts": [
-        "build/npm/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -104,9 +97,7 @@
     "build": "run-p build:transpile build:types",
     "build:dev": "yarn build",
     "build:transpile": "tsx --tsconfig tsconfig.tsnode.json scripts/buildRollup.ts",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "yarn build:watch",
     "build:transpile:watch": "nodemon --ext ts --watch src scripts/buildRollup.ts",
diff --git a/packages/node-core/package.json b/packages/node-core/package.json
index 18c430fa770c..d734ed2f08d9 100644
--- a/packages/node-core/package.json
+++ b/packages/node-core/package.json
@@ -66,13 +66,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/types/index.d.ts": [
-        "build/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -118,9 +111,7 @@
     "build": "run-p build:transpile build:types",
     "build:dev": "yarn build",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "yarn build:watch",
     "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
diff --git a/packages/node-native/package.json b/packages/node-native/package.json
index 2367a658c753..20fec52900c1 100644
--- a/packages/node-native/package.json
+++ b/packages/node-native/package.json
@@ -30,13 +30,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/types/index.d.ts": [
-        "build/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "engines": {
     "node": ">=18"
   },
@@ -54,8 +47,7 @@
     "lint:fix": "OXLINT_TSGOLINT_DANGEROUSLY_SUPPRESS_PROGRAM_DIAGNOSTICS=true oxlint . --fix --type-aware",
     "build": "yarn build:types && yarn build:transpile",
     "build:transpile": "yarn rollup -c rollup.npm.config.mjs",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
-    "build:types": "tsc -p tsconfig.types.json && yarn build:types:downlevel",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:dev": "yarn clean && yarn build",
     "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
     "build:watch": "run-p build:transpile:watch",
diff --git a/packages/node/package.json b/packages/node/package.json
index 4f3f1b142b9c..08ca76230518 100644
--- a/packages/node/package.json
+++ b/packages/node/package.json
@@ -54,13 +54,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/types/index.d.ts": [
-        "build/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -82,9 +75,7 @@
     "build": "run-p build:transpile build:types",
     "build:dev": "yarn build",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "yarn build:watch",
     "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
diff --git a/packages/opentelemetry/package.json b/packages/opentelemetry/package.json
index 482f54bd38c4..618978be16fd 100644
--- a/packages/opentelemetry/package.json
+++ b/packages/opentelemetry/package.json
@@ -37,13 +37,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/types/index.d.ts": [
-        "build/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -65,9 +58,7 @@
     "build": "run-p build:transpile build:types",
     "build:dev": "yarn build",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "yarn build:watch",
     "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
diff --git a/packages/profiling-node/package.json b/packages/profiling-node/package.json
index 099bf124ed39..b3fb655fe2aa 100644
--- a/packages/profiling-node/package.json
+++ b/packages/profiling-node/package.json
@@ -22,13 +22,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/types/index.d.ts": [
-        "build/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "bin": {
     "sentry-prune-profiler-binaries": "scripts/prune-profiler-binaries.js"
   },
@@ -50,8 +43,7 @@
     "lint:fix": "OXLINT_TSGOLINT_DANGEROUSLY_SUPPRESS_PROGRAM_DIAGNOSTICS=true oxlint . --fix --type-aware",
     "build": "yarn build:types && yarn build:transpile",
     "build:transpile": "yarn rollup -c rollup.npm.config.mjs",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
-    "build:types": "tsc -p tsconfig.types.json && yarn build:types:downlevel",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:dev": "yarn clean && yarn build",
     "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
     "build:watch": "run-p build:transpile:watch",
diff --git a/packages/react/package.json b/packages/react/package.json
index 898100aa94b0..aa6b46d69ad9 100644
--- a/packages/react/package.json
+++ b/packages/react/package.json
@@ -32,13 +32,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/types/index.d.ts": [
-        "build/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -75,9 +68,7 @@
     "build": "run-p build:transpile build:types",
     "build:dev": "yarn build",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "yarn build:watch",
     "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
diff --git a/packages/remix/package.json b/packages/remix/package.json
index 273694cc3ac0..4591ec787b92 100644
--- a/packages/remix/package.json
+++ b/packages/remix/package.json
@@ -53,13 +53,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/types/index.d.ts": [
-        "build/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -93,9 +86,7 @@
     "build": "run-p build:transpile build:types",
     "build:dev": "yarn build",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "yarn build:watch",
     "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
diff --git a/packages/replay-canvas/package.json b/packages/replay-canvas/package.json
index d2ec68047952..360b8925d34c 100644
--- a/packages/replay-canvas/package.json
+++ b/packages/replay-canvas/package.json
@@ -19,13 +19,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/npm/types/index.d.ts": [
-        "build/npm/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "files": [
     "/build/npm"
   ],
@@ -35,9 +28,7 @@
     "build:transpile": "rollup -c rollup.npm.config.mjs",
     "build:bundle": "rollup -c rollup.bundle.config.mjs",
     "build:dev": "run-p build:transpile build:types",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/npm/types build/npm/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch build:bundle:watch",
     "build:dev:watch": "run-p build:transpile:watch",
     "build:transpile:watch": "yarn build:transpile --watch",
diff --git a/packages/replay-internal/package.json b/packages/replay-internal/package.json
index 6e021f6d9183..a75264e40639 100644
--- a/packages/replay-internal/package.json
+++ b/packages/replay-internal/package.json
@@ -30,13 +30,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/npm/types/index.d.ts": [
-        "build/npm/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "files": [
     "/build/npm"
   ],
@@ -49,9 +42,7 @@
     "build:transpile": "rollup -c rollup.npm.config.mjs",
     "build:bundle": "rollup -c rollup.bundle.config.mjs",
     "build:dev": "run-p build:transpile build:types",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/npm/types build/npm/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch build:bundle:watch",
     "build:dev:watch": "run-p build:transpile:watch",
     "build:transpile:watch": "yarn build:transpile --watch",
diff --git a/packages/replay-worker/package.json b/packages/replay-worker/package.json
index 7153e090d8b6..4fa9fc6a0a58 100644
--- a/packages/replay-worker/package.json
+++ b/packages/replay-worker/package.json
@@ -22,13 +22,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/types/index.d.ts": [
-        "build/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "files": [
     "/build"
   ],
@@ -38,9 +31,7 @@
     "build": "run-p build:transpile build:types",
     "build:transpile": "rollup -c rollup.worker.config.mjs",
     "build:examples": "rollup -c rollup.examples.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:dev": "yarn build",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "yarn build:watch",
diff --git a/packages/server-utils/package.json b/packages/server-utils/package.json
index cdc79f8570d4..108fa94fe8ea 100644
--- a/packages/server-utils/package.json
+++ b/packages/server-utils/package.json
@@ -51,26 +51,6 @@
     }
   },
   "typesVersions": {
-    "<5.0": {
-      "build/types/index.d.ts": [
-        "build/types-ts3.8/index.d.ts"
-      ],
-      "orchestrion": [
-        "build/types-ts3.8/orchestrion/index.d.ts"
-      ],
-      "orchestrion/config": [
-        "build/types-ts3.8/orchestrion/config/index.d.ts"
-      ],
-      "orchestrion/register": [
-        "build/types-ts3.8/orchestrion/runtime/register.d.ts"
-      ],
-      "orchestrion/vite": [
-        "build/types-ts3.8/orchestrion/bundler/vite.d.ts"
-      ],
-      "orchestrion/webpack": [
-        "build/types-ts3.8/orchestrion/bundler/webpack.d.ts"
-      ]
-    },
     "*": {
       "orchestrion": [
         "build/types/orchestrion/index.d.ts"
@@ -108,9 +88,7 @@
     "build": "run-p build:transpile build:types",
     "build:dev": "yarn build",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8 && node scripts/inject-ts38-shims.mjs",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "run-p build:transpile:watch",
     "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
diff --git a/packages/server-utils/scripts/inject-ts38-shims.mjs b/packages/server-utils/scripts/inject-ts38-shims.mjs
deleted file mode 100644
index 470259a84822..000000000000
--- a/packages/server-utils/scripts/inject-ts38-shims.mjs
+++ /dev/null
@@ -1,28 +0,0 @@
-/**
- * Injects ambient type shims into the downleveled TS 3.8 declarations.
- *
- * `server-utils` re-exports types that reference `node:diagnostics_channel`, a module missing from
- * the `@types/node@14` the TS 3.8 compatibility check uses. We copy a shim declaring that module into
- * the ts3.8 output and reference it from the entry point so it is loaded by downstream consumers.
- * Scoped to ts3.8 only — the modern build resolves the module from `@types/node` directly.
- */
-import { copyFileSync, readFileSync, writeFileSync } from 'node:fs';
-import { dirname, join } from 'node:path';
-import { fileURLToPath } from 'node:url';
-
-const packageRoot = join(dirname(fileURLToPath(import.meta.url)), '..');
-const ts38Dir = join(packageRoot, 'build', 'types-ts3.8');
-
-const SHIM_FILENAME = 'node-diagnostics-channel.d.ts';
-const shimSource = join(packageRoot, 'types-shims', SHIM_FILENAME);
-const shimTarget = join(ts38Dir, SHIM_FILENAME);
-
-copyFileSync(shimSource, shimTarget);
-
-const entry = join(ts38Dir, 'index.d.ts');
-const reference = `/// <reference path="./${SHIM_FILENAME}" />\n`;
-const contents = readFileSync(entry, 'utf8');
-
-if (!contents.startsWith(reference)) {
-  writeFileSync(entry, reference + contents);
-}
diff --git a/packages/server-utils/types-shims/node-diagnostics-channel.d.ts b/packages/server-utils/types-shims/node-diagnostics-channel.d.ts
deleted file mode 100644
index 69f0a7467863..000000000000
--- a/packages/server-utils/types-shims/node-diagnostics-channel.d.ts
+++ /dev/null
@@ -1,19 +0,0 @@
-/**
- * Ambient shim for `node:diagnostics_channel`, injected into the TS 3.8 type output only
- * (see `scripts/inject-ts38-shims.mjs`).
- *
- * `@types/node@14` — used by the SDK's TS 3.8 compatibility check — predates this module, so the
- * published declarations that re-export `TracingChannel`/`TracingChannelSubscribers` fail to resolve
- * it (`TS2307`). The real shapes are irrelevant here: TS 3.8 consumers only need these to type-check,
- * never to call. This file is deliberately kept out of `src/` so it never participates in the modern
- * build, where `@types/node` already declares the module.
- */
-declare module 'node:diagnostics_channel' {
-  export interface TracingChannelSubscribers<ContextType = unknown> {
-    [key: string]: unknown;
-  }
-
-  export interface TracingChannel<StoreType = unknown, ContextType = unknown> {
-    [key: string]: unknown;
-  }
-}
diff --git a/packages/svelte/package.json b/packages/svelte/package.json
index ce1de2994576..4d731d54826d 100644
--- a/packages/svelte/package.json
+++ b/packages/svelte/package.json
@@ -28,13 +28,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/types/index.d.ts": [
-        "build/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -56,9 +49,7 @@
     "build": "run-p build:transpile build:types",
     "build:dev": "yarn build",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "yarn build:watch",
     "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
diff --git a/packages/tanstackstart-react/package.json b/packages/tanstackstart-react/package.json
index 2b1bcddc2b18..805780262cc5 100644
--- a/packages/tanstackstart-react/package.json
+++ b/packages/tanstackstart-react/package.json
@@ -52,13 +52,6 @@
       "require": "./build/cjs/vite/index.js"
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/npm/types/index.d.ts": [
-        "build/npm/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -78,9 +71,7 @@
     "build": "run-p build:transpile build:types",
     "build:dev": "yarn build",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "yarn build:watch",
     "build:transpile:watch": "nodemon --ext ts --watch src scripts/buildRollup.ts",
diff --git a/packages/tanstackstart/package.json b/packages/tanstackstart/package.json
index bbecf0b35f4a..c0afb48d12c6 100644
--- a/packages/tanstackstart/package.json
+++ b/packages/tanstackstart/package.json
@@ -29,13 +29,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/npm/types/index.d.ts": [
-        "build/npm/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -43,9 +36,7 @@
     "build": "run-p build:transpile build:types",
     "build:dev": "yarn build",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "yarn build:watch",
     "build:transpile:watch": "nodemon --ext ts --watch src scripts/buildRollup.ts",
diff --git a/packages/types/package.json b/packages/types/package.json
index 81ddd5c3a0e4..621a57c8b114 100644
--- a/packages/types/package.json
+++ b/packages/types/package.json
@@ -28,13 +28,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/types/index.d.ts": [
-        "build/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -42,9 +35,7 @@
     "build": "run-p build:transpile build:types",
     "build:dev": "yarn build",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "yarn build:watch",
     "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
diff --git a/packages/vercel-edge/package.json b/packages/vercel-edge/package.json
index b5ddeb84e68a..9c53e9ff70af 100644
--- a/packages/vercel-edge/package.json
+++ b/packages/vercel-edge/package.json
@@ -28,13 +28,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/types/index.d.ts": [
-        "build/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -51,9 +44,7 @@
     "build": "run-p build:transpile build:types",
     "build:dev": "yarn build",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "yarn build:watch",
     "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
diff --git a/packages/vue/package.json b/packages/vue/package.json
index f6ddf3fb5068..2a129b051585 100644
--- a/packages/vue/package.json
+++ b/packages/vue/package.json
@@ -40,13 +40,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/types/index.d.ts": [
-        "build/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -76,10 +69,9 @@
     "build": "run-p build:transpile build:types",
     "build:dev": "run-p build:transpile build:types",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:router build:types:downlevel",
+    "build:types": "run-s build:types:core build:types:router",
     "build:types:core": "tsc -p tsconfig.types.json",
     "build:types:router": "tsc -p tsconfig.router-types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
     "build:watch": "run-p build:transpile:watch",
     "build:dev:watch": "run-p build:transpile:watch",
     "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
diff --git a/packages/wasm/package.json b/packages/wasm/package.json
index 790c7e08ba27..634e5ce4962f 100644
--- a/packages/wasm/package.json
+++ b/packages/wasm/package.json
@@ -28,13 +28,6 @@
       }
     }
   },
-  "typesVersions": {
-    "<5.0": {
-      "build/npm/types/index.d.ts": [
-        "build/npm/types-ts3.8/index.d.ts"
-      ]
-    }
-  },
   "publishConfig": {
     "access": "public"
   },
@@ -47,9 +40,7 @@
     "build:bundle": "rollup --config rollup.bundle.config.mjs",
     "build:dev": "run-p build:transpile build:types",
     "build:transpile": "rollup -c rollup.npm.config.mjs",
-    "build:types": "run-s build:types:core build:types:downlevel",
-    "build:types:core": "tsc -p tsconfig.types.json",
-    "build:types:downlevel": "yarn downlevel-dts build/npm/types build/npm/types-ts3.8 --to ts3.8",
+    "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:transpile:watch build:bundle:watch",
     "build:bundle:watch": "rollup --config rollup.bundle.config.mjs --watch",
     "build:dev:watch": "run-p build:transpile:watch",
diff --git a/scripts/report-ci-failures.mjs b/scripts/report-ci-failures.mjs
index 07a6d7cef3bd..903d33f387bc 100644
--- a/scripts/report-ci-failures.mjs
+++ b/scripts/report-ci-failures.mjs
@@ -25,7 +25,7 @@ import { readFileSync } from 'node:fs';
  *
  *   "Node (22) Integration Tests"          -> "Node Integration Tests"
  *   "Node (24) Integration Tests"          -> "Node Integration Tests"
- *   "Node (24) (TS 3.8) Integration Tests" -> "Node Integration Tests"
+ *   "Node (24) (TS 5.0) Integration Tests" -> "Node Integration Tests"
  */
 function normalizeJobName(name) {
   return name
diff --git a/yarn.lock b/yarn.lock
index 97db74ecf6ab..c296d1f560c2 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -14501,15 +14501,6 @@ dotenv@^16.3.1, dotenv@^16.4.5, dotenv@^16.6.1:
   resolved "https://registry.yarnpkg.com/dotenv/-/dotenv-16.6.1.tgz#773f0e69527a8315c7285d5ee73c4459d20a8020"
   integrity sha512-uBq4egWHTcTt33a72vpSG0z3HnPuIl6NqYcTrKEg2azoEyl2hpW0zqlxysq2pK9HlDIHyHyakeYaYnSAwd8bow==
 
-downlevel-dts@~0.11.0:
-  version "0.11.0"
-  resolved "https://registry.yarnpkg.com/downlevel-dts/-/downlevel-dts-0.11.0.tgz#514a2d723009c5845730c1db6c994484c596ed9c"
-  integrity sha512-vo835pntK7kzYStk7xUHDifiYJvXxVhUapt85uk2AI94gUUAQX9HNRtrcMHNSc3YHJUEHGbYIGsM99uIbgAtxw==
-  dependencies:
-    semver "^7.3.2"
-    shelljs "^0.8.3"
-    typescript next
-
 dset@^3.1.2:
   version "3.1.4"
   resolved "https://registry.yarnpkg.com/dset/-/dset-3.1.4.tgz#f8eaf5f023f068a036d08cd07dc9ffb7d0065248"
@@ -17709,7 +17700,7 @@ glob@^5.0.10:
     once "^1.3.0"
     path-is-absolute "^1.0.0"
 
-glob@^7.0.0, glob@^7.1.2, glob@^7.1.3, glob@^7.1.4, glob@^7.1.6, glob@^7.2.3:
+glob@^7.1.2, glob@^7.1.3, glob@^7.1.4, glob@^7.1.6, glob@^7.2.3:
   version "7.2.3"
   resolved "https://registry.yarnpkg.com/glob/-/glob-7.2.3.tgz#b8df0fb802bbfa8e89bd1d938b4e16578ed44f2b"
   integrity sha512-nFR0zLpU2YCaRxwoCJvL6UvCH2JFyFVIvwTLsIf21AuHlMskA1hhTdk+LlYJtOlYt9v6dvszD2BGRqBL+iQK9Q==
@@ -18899,11 +18890,6 @@ internal-slot@^1.0.3, internal-slot@^1.1.0:
     hasown "^2.0.2"
     side-channel "^1.1.0"
 
-interpret@^1.0.0:
-  version "1.4.0"
-  resolved "https://registry.yarnpkg.com/interpret/-/interpret-1.4.0.tgz#665ab8bc4da27a774a40584e812e3e0fa45b1a1e"
-  integrity sha512-agE4QfB2Lkp9uICn7BAqoscw4SZP9kTE2hxiFI3jBPmXJfdqiahTbUuKGsMoN2GtqL9AxhYioAcVvgsb1HvRbA==
-
 interpret@^2.2.0:
   version "2.2.0"
   resolved "https://registry.yarnpkg.com/interpret/-/interpret-2.2.0.tgz#1a78a0b5965c40a5416d007ad6f50ad27c417df9"
@@ -25588,13 +25574,6 @@ recast@^0.23.4:
     tiny-invariant "^1.3.3"
     tslib "^2.0.1"
 
-rechoir@^0.6.2:
-  version "0.6.2"
-  resolved "https://registry.yarnpkg.com/rechoir/-/rechoir-0.6.2.tgz#85204b54dba82d5742e28c96756ef43af50e3384"
-  integrity sha1-hSBLVNuoLVdC4oyWdW70OvUOM4Q=
-  dependencies:
-    resolve "^1.1.6"
-
 rechoir@^0.8.0:
   version "0.8.0"
   resolved "https://registry.yarnpkg.com/rechoir/-/rechoir-0.8.0.tgz#49f866e0d32146142da3ad8f0eff352b3215ff22"
@@ -26093,7 +26072,7 @@ resolve@1.22.1:
     path-parse "^1.0.7"
     supports-preserve-symlinks-flag "^1.0.0"
 
-resolve@^1.1.6, resolve@^1.1.7, resolve@^1.10.0, resolve@^1.10.1, resolve@^1.11.1, resolve@^1.12.0, resolve@^1.13.1, resolve@^1.14.2, resolve@^1.17.0, resolve@^1.19.0, resolve@^1.20.0, resolve@^1.22.0, resolve@^1.22.1, resolve@^1.22.10, resolve@^1.22.4, resolve@^1.22.8, resolve@^1.4.0, resolve@^1.5.0:
+resolve@^1.1.7, resolve@^1.10.0, resolve@^1.10.1, resolve@^1.11.1, resolve@^1.12.0, resolve@^1.13.1, resolve@^1.14.2, resolve@^1.17.0, resolve@^1.19.0, resolve@^1.20.0, resolve@^1.22.0, resolve@^1.22.1, resolve@^1.22.10, resolve@^1.22.4, resolve@^1.22.8, resolve@^1.4.0, resolve@^1.5.0:
   version "1.22.10"
   resolved "https://registry.yarnpkg.com/resolve/-/resolve-1.22.10.tgz#b663e83ffb09bbf2386944736baae803029b8b39"
   integrity sha512-NPRy+/ncIMeDlTAsuqwKIiferiawhefFJtkNSW0qZJEqMEb+qBt/77B/jGeeek+F0uOeN05CDa6HXbbIgtVX4w==
@@ -26981,15 +26960,6 @@ shell-quote@^1.7.3, shell-quote@^1.8.4:
   resolved "https://registry.yarnpkg.com/shell-quote/-/shell-quote-1.8.4.tgz#2edd9a4dcefc96649e2e2cb12f637b1f1d92a190"
   integrity sha512-VsC6n6vz1ihYYyZZwX7YZSF5l5x36ca17OC+a69h94YqB7X6XLwf+5MOgynYir2SLFUbl8gIYvBo8K8RoNQ6bQ==
 
-shelljs@^0.8.3:
-  version "0.8.5"
-  resolved "https://registry.yarnpkg.com/shelljs/-/shelljs-0.8.5.tgz#de055408d8361bed66c669d2f000538ced8ee20c"
-  integrity sha512-TiwcRcrkhHvbrZbnRcFYMLl30Dfov3HKqzp5tO5b4pt6G/SezKcYhmDg15zXVBswHmctSAQKznqNW2LO5tTDow==
-  dependencies:
-    glob "^7.0.0"
-    interpret "^1.0.0"
-    rechoir "^0.6.2"
-
 shellwords@^0.1.1:
   version "0.1.1"
   resolved "https://registry.yarnpkg.com/shellwords/-/shellwords-0.1.1.tgz#d6b9181c1a48d397324c84871efbcfc73fc0654b"
@@ -29029,11 +28999,6 @@ typescript@^5.7.3, typescript@^5.8.3:
   resolved "https://registry.yarnpkg.com/typescript/-/typescript-5.9.3.tgz#5b4f59e15310ab17a216f5d6cf53ee476ede670f"
   integrity sha512-jl1vZzPDinLr9eUt3J/t7V6FgNEw9QjvBPdysz9KfQDD41fQrC2Y4vKQdiaUpFT4bXlb1RHhLpp8wtm6M5TgSw==
 
-typescript@next:
-  version "5.2.0-dev.20230530"
-  resolved "https://registry.yarnpkg.com/typescript/-/typescript-5.2.0-dev.20230530.tgz#4251ade97a9d8a86850c4d5c3c4f3e1cb2ccf52c"
-  integrity sha512-bIoMajCZWzLB+pWwncaba/hZc6dRnw7x8T/fenOnP9gYQB/gc4xdm48AXp5SH5I/PvvSeZ/dXkUMtc8s8BiDZw==
-
 typescript@~5.8.0:
   version "5.8.3"
   resolved "https://registry.yarnpkg.com/typescript/-/typescript-5.8.3.tgz#92f8a3e5e3cf497356f4178c34cd65a7f5e8440e"