diff --git a/packages/core/tests/dev/error.test.ts b/packages/core/tests/dev/error.test.ts
index 3fe835d..1c1dfc8 100644
--- a/packages/core/tests/dev/error.test.ts
+++ b/packages/core/tests/dev/error.test.ts
@@ -3,23 +3,26 @@ import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 
 describe("dev error fixture", () => {
   let fixture: ReturnType<typeof getFixture>;
+  let stop: () => Promise<void>;
 
   beforeEach(() => {
     fixture = getFixture("dev.basic");
+    stop = () => fixture.clean();
     vi.spyOn(console, "error").mockImplementation(() => {});
   });
 
   afterEach(async () => {
     vi.restoreAllMocks();
-    await fixture.clean();
+    await stop();
   });
 
   it("renders the Astro error overlay", async () => {
-    const { render } = await fixture.startDevServer({
+    const devServer = await fixture.startDevServer({
       config: { logLevel: "silent" },
     });
+    stop = devServer.stop;
 
-    const response = await render({
+    const response = await devServer.render({
       component: "error",
       partial: false,
     });
@@ -30,15 +33,16 @@ describe("dev error fixture", () => {
   });
 
   it("throws an error when hmr.overlay is false", async () => {
-    const { render } = await fixture.startDevServer({
+    const devServer = await fixture.startDevServer({
       config: {
         logLevel: "silent",
         vite: { server: { hmr: { overlay: false } } },
       },
     });
+    stop = devServer.stop;
 
     await expect(
-      render({
+      devServer.render({
         component: "error",
         partial: false,
       }),
diff --git a/packages/core/tests/fixture.ts b/packages/core/tests/fixture.ts
index 482cd14..87514c5 100644
--- a/packages/core/tests/fixture.ts
+++ b/packages/core/tests/fixture.ts
@@ -47,19 +47,20 @@ export function getFixture(fixtureName: string): {
     `dist-${Math.random().toString(36).substring(2, 15)}`,
   );
 
+  // Isolate Vite dep-optimization cache per Vitest run to prevent
+  // ENOTEMPTY race when multiple `pnpm test` processes run in parallel.
+  const viteCacheDir = path.join(
+    import.meta.dirname,
+    "..",
+    "node_modules",
+    `.vite-${process.ppid || process.pid}`,
+  );
+
   const clean = async () => {
     await rm(outDir, {
       recursive: true,
       force: true,
     });
-    await rm(path.join(fixtureRoot, ".astro"), {
-      recursive: true,
-      force: true,
-    });
-    await rm(path.join(fixtureRoot, "node_modules"), {
-      recursive: true,
-      force: true,
-    });
   };
 
   const DEV_TEST_ADDRESS = "http://host-placeholder.test";
@@ -78,6 +79,7 @@ export function getFixture(fixtureName: string): {
           {
             root: fixtureRoot,
             logLevel: "warn",
+            vite: { cacheDir: viteCacheDir },
           },
           params?.config ?? {},
         ),
@@ -115,6 +117,7 @@ export function getFixture(fixtureName: string): {
             outDir,
             logLevel: "warn",
             vite: {
+              cacheDir: viteCacheDir,
               build: {
                 rollupOptions: { external: ["@/context"] },
               },
diff --git a/packages/core/vitest.config.ts b/packages/core/vitest.config.ts
index 53fea7a..b95d3a5 100644
--- a/packages/core/vitest.config.ts
+++ b/packages/core/vitest.config.ts
@@ -8,6 +8,7 @@ export default defineConfig({
       "@/": `${path.resolve(import.meta.dirname, "src")}/`,
       "@tests/": `${path.resolve(import.meta.dirname, "tests")}/`,
     },
-    testTimeout: 30000,
+    testTimeout: 120000,
+    hookTimeout: 60000,
   },
 });
diff --git a/packages/hono/tests/cli.test.ts b/packages/hono/tests/cli.test.ts
index 51ddaf2..42f6593 100644
--- a/packages/hono/tests/cli.test.ts
+++ b/packages/hono/tests/cli.test.ts
@@ -1,4 +1,4 @@
-import { readFile } from "node:fs/promises";
+import { mkdir, readFile, symlink } from "node:fs/promises";
 import path from "node:path";
 import { afterEach, beforeEach, describe, expect, it } from "vitest";
 import { runCli } from "../src/cli/run";
@@ -30,12 +30,25 @@ describe("cli", () => {
   });
 
   it("builds the fixture when --root is provided before the command", async () => {
-    await expect(
-      runCli(["--root", fixture.fixtureRoot, "build"]),
-    ).resolves.toBe(undefined);
+    // Use the unique outDir as a build root (with symlinks to fixture source)
+    // to avoid parallel build conflicts on the shared dist/ directory.
+    const buildRoot = fixture.outDir;
+    await mkdir(buildRoot, { recursive: true });
+    await symlink(
+      path.join(fixture.fixtureRoot, "astro.config.ts"),
+      path.join(buildRoot, "astro.config.ts"),
+    );
+    await symlink(
+      path.join(fixture.fixtureRoot, "src"),
+      path.join(buildRoot, "src"),
+    );
+
+    await expect(runCli(["--root", buildRoot, "build"])).resolves.toBe(
+      undefined,
+    );
 
     const output = await readFile(
-      path.join(fixture.fixtureRoot, "dist", "client", "index.html"),
+      path.join(buildRoot, "dist", "client", "index.html"),
       "utf-8",
     );
 
diff --git a/packages/hono/tests/fixture.ts b/packages/hono/tests/fixture.ts
index 03149b6..1c660d0 100644
--- a/packages/hono/tests/fixture.ts
+++ b/packages/hono/tests/fixture.ts
@@ -42,20 +42,17 @@ export function getFixture(fixtureName: string): {
     `dist-${Math.random().toString(36).substring(2, 15)}`,
   );
 
+  // Isolate Vite dep-optimization cache per Vitest run to prevent
+  // ENOTEMPTY race when multiple `pnpm test` processes run in parallel.
+  const viteCacheDir = path.join(
+    import.meta.dirname,
+    "..",
+    "node_modules",
+    `.vite-${process.ppid || process.pid}`,
+  );
+
   const clean = async (): Promise<void> => {
     await rm(outDir, { recursive: true, force: true });
-    await rm(path.join(fixtureRoot, "dist"), {
-      recursive: true,
-      force: true,
-    });
-    await rm(path.join(fixtureRoot, ".astro"), {
-      recursive: true,
-      force: true,
-    });
-    await rm(path.join(fixtureRoot, "node_modules"), {
-      recursive: true,
-      force: true,
-    });
   };
 
   return {
@@ -69,6 +66,7 @@ export function getFixture(fixtureName: string): {
             outDir,
             logLevel: "warn",
             vite: {
+              cacheDir: viteCacheDir,
               build: {
                 rollupOptions: {
                   external: ["@gomighty/core/context"],
@@ -94,7 +92,11 @@ export function getFixture(fixtureName: string): {
       const middleware = devMiddleware({
         ...params,
         config: mergeConfig<AstroInlineConfig>(
-          { root: fixtureRoot, logLevel: "warn" },
+          {
+            root: fixtureRoot,
+            logLevel: "warn",
+            vite: { cacheDir: viteCacheDir },
+          },
           params?.config ?? {},
         ),
       });
diff --git a/packages/hono/vitest.config.ts b/packages/hono/vitest.config.ts
index 20a75d0..7b6aeb5 100644
--- a/packages/hono/vitest.config.ts
+++ b/packages/hono/vitest.config.ts
@@ -7,6 +7,7 @@ export default defineConfig({
     alias: {
       "@/": `${path.resolve(import.meta.dirname, "src")}/`,
     },
-    testTimeout: 30000,
+    testTimeout: 120000,
+    hookTimeout: 60000,
   },
 });
diff --git a/vitest.config.ts b/vitest.config.ts
index 7959d17..4968b89 100644
--- a/vitest.config.ts
+++ b/vitest.config.ts
@@ -3,6 +3,7 @@ import { defineConfig } from "vitest/config";
 export default defineConfig({
   test: {
     projects: ["packages/*"],
-    testTimeout: 30000,
+    testTimeout: 120000,
+    hookTimeout: 60000,
   },
 });