Fixed compiler warning
diff --git a/src/video/uikit/SDL_uikitvideo.h b/src/video/uikit/SDL_uikitvideo.h
index 736888c..cf90042 100644
--- a/src/video/uikit/SDL_uikitvideo.h
+++ b/src/video/uikit/SDL_uikitvideo.h
@@ -29,7 +29,7 @@
@interface SDL_VideoData : NSObject
-@property (nonatomic) id pasteboardObserver;
+@property (nonatomic, assign) id pasteboardObserver;
@end