diff --git a/libraries/exoplayer_ima/src/main/java/androidx/media3/exoplayer/ima/ImaServerSideAdInsertionMediaSource.java b/libraries/exoplayer_ima/src/main/java/androidx/media3/exoplayer/ima/ImaServerSideAdInsertionMediaSource.java
index 7c2751ce91..1d9eb0c9f8 100644
--- a/libraries/exoplayer_ima/src/main/java/androidx/media3/exoplayer/ima/ImaServerSideAdInsertionMediaSource.java
+++ b/libraries/exoplayer_ima/src/main/java/androidx/media3/exoplayer/ima/ImaServerSideAdInsertionMediaSource.java
@@ -698,7 +698,9 @@ public final class ImaServerSideAdInsertionMediaSource extends CompositeMediaSou
 
   @MainThread
   private void invalidateServerSideAdInsertionAdPlaybackState() {
-    if (!adPlaybackState.equals(AdPlaybackState.NONE) && contentTimeline != null) {
+    if (!adPlaybackState.equals(AdPlaybackState.NONE)
+        && contentTimeline != null
+        && serverSideAdInsertionMediaSource != null) {
       Timeline contentTimeline = checkNotNull(this.contentTimeline);
       ImmutableMap<Object, AdPlaybackState> splitAdPlaybackStates;
       if (Objects.equals(streamRequest.getFormat(), StreamFormat.DASH)) {