diff --git a/extensions/ima/src/main/java/com/google/android/exoplayer2/ext/ima/ImaServerSideAdInsertionMediaSource.java b/extensions/ima/src/main/java/com/google/android/exoplayer2/ext/ima/ImaServerSideAdInsertionMediaSource.java
index 82762f1df3..8e3cfc6ce7 100644
--- a/extensions/ima/src/main/java/com/google/android/exoplayer2/ext/ima/ImaServerSideAdInsertionMediaSource.java
+++ b/extensions/ima/src/main/java/com/google/android/exoplayer2/ext/ima/ImaServerSideAdInsertionMediaSource.java
@@ -36,6 +36,7 @@ import android.content.Context;
 import android.net.Uri;
 import android.os.Bundle;
 import android.os.Handler;
+import android.os.Looper;
 import android.util.Pair;
 import android.view.ViewGroup;
 import androidx.annotation.IntDef;
@@ -493,7 +494,8 @@ public final class ImaServerSideAdInsertionMediaSource extends CompositeMediaSou
     this.applicationAdEventListener = applicationAdEventListener;
     this.applicationAdErrorListener = applicationAdErrorListener;
     componentListener = new ComponentListener();
-    mainHandler = Util.createHandlerForCurrentLooper();
+    Assertions.checkArgument(player.getApplicationLooper() == Looper.getMainLooper());
+    mainHandler = new Handler(Looper.getMainLooper());
     Uri streamRequestUri = checkNotNull(mediaItem.localConfiguration).uri;
     isLiveStream = ImaServerSideAdInsertionUriBuilder.isLiveStream(streamRequestUri);
     adsId = ImaServerSideAdInsertionUriBuilder.getAdsId(streamRequestUri);
@@ -570,8 +572,11 @@ public final class ImaServerSideAdInsertionMediaSource extends CompositeMediaSou
     super.releaseSourceInternal();
     if (loader != null) {
       loader.release();
-      player.removeListener(componentListener);
-      mainHandler.post(() -> setStreamManager(/* streamManager= */ null));
+      mainHandler.post(
+          () -> {
+            player.removeListener(componentListener);
+            setStreamManager(/* streamManager= */ null);
+          });
       loader = null;
     }
   }