diff --git a/packages/react-native-nitro-fetch/android/build.gradle b/packages/react-native-nitro-fetch/android/build.gradle
index 847ad9b4..0066c74a 100644
--- a/packages/react-native-nitro-fetch/android/build.gradle
+++ b/packages/react-native-nitro-fetch/android/build.gradle
@@ -21,7 +21,14 @@ def reactNativeArchitectures() {
 }
 
 apply plugin: "com.android.library"
-apply plugin: "kotlin-android"
+// AGP 9 ships built-in Kotlin support and registers the `kotlin` extension
+// itself. Applying the Kotlin plugin on top of it fails configuration with
+// "Cannot add extension with name 'kotlin'". Only apply it when nothing has
+// registered that extension yet.
+if (project.extensions.findByName('kotlin') == null) {
+  apply plugin: "kotlin-android"
+}
+
 apply from: '../nitrogen/generated/android/nitrofetch+autolinking.gradle'
 
 // Do not apply React Gradle plugin in library to avoid RN codegen duplicating app classes
diff --git a/packages/react-native-nitro-text-decoder/android/build.gradle b/packages/react-native-nitro-text-decoder/android/build.gradle
index a3742f10..4bd974ad 100644
--- a/packages/react-native-nitro-text-decoder/android/build.gradle
+++ b/packages/react-native-nitro-text-decoder/android/build.gradle
@@ -19,7 +19,14 @@ def isNewArchitectureEnabled() {
 }
 
 apply plugin: "com.android.library"
-apply plugin: 'org.jetbrains.kotlin.android'
+// AGP 9 ships built-in Kotlin support and registers the `kotlin` extension
+// itself. Applying the Kotlin plugin on top of it fails configuration with
+// "Cannot add extension with name 'kotlin'". Only apply it when nothing has
+// registered that extension yet.
+if (project.extensions.findByName('kotlin') == null) {
+  apply plugin: 'org.jetbrains.kotlin.android'
+}
+
 apply from: '../nitrogen/generated/android/NitroTextDecoder+autolinking.gradle'
 apply from: "./fix-prefab.gradle"
 
diff --git a/packages/react-native-nitro-websockets/android/build.gradle b/packages/react-native-nitro-websockets/android/build.gradle
index 2d3e987e..059cc28f 100644
--- a/packages/react-native-nitro-websockets/android/build.gradle
+++ b/packages/react-native-nitro-websockets/android/build.gradle
@@ -19,7 +19,14 @@ def isNewArchitectureEnabled() {
 }
 
 apply plugin: "com.android.library"
-apply plugin: 'org.jetbrains.kotlin.android'
+// AGP 9 ships built-in Kotlin support and registers the `kotlin` extension
+// itself. Applying the Kotlin plugin on top of it fails configuration with
+// "Cannot add extension with name 'kotlin'". Only apply it when nothing has
+// registered that extension yet.
+if (project.extensions.findByName('kotlin') == null) {
+  apply plugin: 'org.jetbrains.kotlin.android'
+}
+
 apply from: '../nitrogen/generated/android/NitroFetchWebsockets+autolinking.gradle'
 apply from: "./fix-prefab.gradle"