diff --git a/src/avfoundation.cs b/src/avfoundation.cs
index 8c5cd5ed..d27ac1e8 100644
--- a/src/avfoundation.cs
+++ b/src/avfoundation.cs
@@ -4292,10 +4292,10 @@ interface AVQueuePlayer {
 		void AdvanceToNextItem ();
 
 		[Export ("canInsertItem:afterItem:")]
-		bool CanInsert (AVPlayerItem item, AVPlayerItem afterItem);
+		bool CanInsert (AVPlayerItem item, [NullAllowed] AVPlayerItem afterItem);
 
 		[Export ("insertItem:afterItem:")]
-		void InsertItem (AVPlayerItem item, AVPlayerItem afterItem);
+		void InsertItem (AVPlayerItem item, [NullAllowed] AVPlayerItem afterItem);
 
 		[Export ("removeItem:")]
 		void RemoveItem (AVPlayerItem item);