diff --git a/media/c2/aidl/aidl_api/android.hardware.media.c2/current/android/hardware/media/c2/IGraphicBufferAllocator.aidl b/media/c2/aidl/aidl_api/android.hardware.media.c2/current/android/hardware/media/c2/IGraphicBufferAllocator.aidl
index 3e460dd..e13ba1f 100644
--- a/media/c2/aidl/aidl_api/android.hardware.media.c2/current/android/hardware/media/c2/IGraphicBufferAllocator.aidl
+++ b/media/c2/aidl/aidl_api/android.hardware.media.c2/current/android/hardware/media/c2/IGraphicBufferAllocator.aidl
@@ -39,7 +39,7 @@
   ParcelFileDescriptor getWaitableFd();
   parcelable Allocation {
     android.hardware.HardwareBuffer buffer;
-    ParcelFileDescriptor fence;
+    @nullable ParcelFileDescriptor fence;
   }
   parcelable Description {
     int width;
diff --git a/media/c2/aidl/android/hardware/media/c2/IGraphicBufferAllocator.aidl b/media/c2/aidl/android/hardware/media/c2/IGraphicBufferAllocator.aidl
index 49c4ea4..1710242 100644
--- a/media/c2/aidl/android/hardware/media/c2/IGraphicBufferAllocator.aidl
+++ b/media/c2/aidl/android/hardware/media/c2/IGraphicBufferAllocator.aidl
@@ -35,7 +35,7 @@
      */
     parcelable Allocation {
         HardwareBuffer buffer;
-        ParcelFileDescriptor fence;
+        @nullable ParcelFileDescriptor fence;
     }
 
     /**