diff --git a/android/build.gradle b/android/build.gradle
index a8a2416fb..9ec049bb5 100644
--- a/android/build.gradle
+++ b/android/build.gradle
@@ -12,7 +12,13 @@ buildscript {
 }
 
 apply plugin: 'com.android.library'
-apply plugin: 'kotlin-android'
+// AGP 9 ships built-in Kotlin support and registers the `kotlin` extension
+// itself. Applying kotlin-android on top of it fails 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'
+}
 
 def getExtOrDefault(name) {
     return rootProject.ext.has(name) ? rootProject.ext.get(name) : project.properties['Purchases_' + name]
diff --git a/react-native-purchases-ui/android/build.gradle b/react-native-purchases-ui/android/build.gradle
index 1309b9cda..ec7984851 100644
--- a/react-native-purchases-ui/android/build.gradle
+++ b/react-native-purchases-ui/android/build.gradle
@@ -19,7 +19,13 @@ def isNewArchitectureEnabled() {
 }
 
 apply plugin: "com.android.library"
-apply plugin: "kotlin-android"
+// AGP 9 ships built-in Kotlin support and registers the `kotlin` extension
+// itself. Applying kotlin-android on top of it fails 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"
+}
 
 if (isNewArchitectureEnabled()) {
   apply plugin: "com.facebook.react"