diff --git a/services/core/java/com/android/server/am/PendingIntentRecord.java b/services/core/java/com/android/server/am/PendingIntentRecord.java
index 550c37af5db23..483fec67a429f 100644
--- a/services/core/java/com/android/server/am/PendingIntentRecord.java
+++ b/services/core/java/com/android/server/am/PendingIntentRecord.java
@@ -219,6 +219,9 @@ final class PendingIntentRecord extends IIntentSender.Stub {
     }
 
     public void unregisterCancelListenerLocked(IResultReceiver receiver) {
+        if (mCancelCallbacks == null) {
+            return; // Already unregistered or detached.
+        }
         mCancelCallbacks.unregister(receiver);
         if (mCancelCallbacks.getRegisteredCallbackCount() <= 0) {
             mCancelCallbacks = null;