diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index ca575026..5e57197d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -11,7 +11,7 @@ jobs:
     name: Flutter version ${{ matrix.flutter_version }} (Android)
     strategy:
       matrix:
-        flutter_version: ["3.29.2"]
+        flutter_version: ["3.38.5"]
 
     steps:
       - uses: actions/checkout@v4
@@ -87,7 +87,7 @@ jobs:
     name: Flutter version ${{ matrix.flutter_version }} (iOS)
     strategy:
       matrix:
-        flutter_version: ["3.29.2"]
+        flutter_version: ["3.38.5"]
 
     steps:
       - uses: actions/checkout@v4
diff --git a/build_tools/SDK_VERSION b/build_tools/SDK_VERSION
index bef80db4..f94ed442 100644
--- a/build_tools/SDK_VERSION
+++ b/build_tools/SDK_VERSION
@@ -1 +1 @@
-3.38.4
+3.38.5
diff --git a/rollbar_flutter/android/build.gradle b/rollbar_flutter/android/build.gradle
index 9ce3a409..4432bc2f 100644
--- a/rollbar_flutter/android/build.gradle
+++ b/rollbar_flutter/android/build.gradle
@@ -167,17 +167,7 @@ task spotbugsMain(type: com.github.spotbugs.snom.SpotBugsTask) {
     }
 }
 
-String flutterCompatVersion = Paths
-    .get(flutterRoot, "version")
-    .toFile()
-    .text
-    .trim()
-
-if (flutterCompatVersion.startsWith('1.')) {
-    android.sourceSets.test.java.srcDir file('src/testflutter1/java/')
-} else {
-    android.sourceSets.test.java.srcDir file('src/testflutter/java/')
-}
+android.sourceSets.test.java.srcDir file('src/testflutter/java/')
 
 afterEvaluate {
     if (project.tasks.getByName("check")) {
diff --git a/rollbar_flutter/android/src/testflutter1/java/com/rollbar/flutter/compatibility/CodecAdapter.java b/rollbar_flutter/android/src/testflutter1/java/com/rollbar/flutter/compatibility/CodecAdapter.java
deleted file mode 100644
index 4967bdb9..00000000
--- a/rollbar_flutter/android/src/testflutter1/java/com/rollbar/flutter/compatibility/CodecAdapter.java
+++ /dev/null
@@ -1,38 +0,0 @@
-package com.rollbar.flutter.compatibility;
-
-import org.mockito.ArgumentCaptor;
-import org.mockito.ArgumentMatchers;
-import org.mockito.verification.VerificationMode;
-
-import java.nio.ByteBuffer;
-
-import io.flutter.plugin.common.MethodCodec;
-
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.ArgumentMatchers.anyString;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
-
-public class CodecAdapter {
-  public static void whenCodecInvoked(MethodCodec codec, ByteBuffer result) {
-    when(codec.encodeErrorEnvelope(
-            ArgumentMatchers.anyString(),
-            ArgumentMatchers.anyString(),
-            any())).thenReturn(result);
-  }
-
-  public static void verifyCall(MethodCodec codec, VerificationMode times,
-                                ArgumentCaptor<String> message,
-                                ArgumentCaptor<String> ignoredStackTrace) {
-    verify(codec, times).encodeErrorEnvelope(
-            anyString(),
-            message.capture(),
-            any()
-    );
-  }
-
-  public static boolean canCaptureStackTrace() {
-    // This is the Flutter 1 implementation, `encodeErrorEnvelope` doesn't accept a stack trace
-    return false;
-  }
-}