--- a/cocoa/ScintillaView.h
+++ b/cocoa/ScintillaView.h
@@ -48,7 +48,7 @@
  * InnerView is the Cocoa interface to the Scintilla backend. It handles text input and
  * provides a canvas for painting the output.
  */
-@interface InnerView : NSView <NSTextInputClient>
+@interface InnerView : NSView <NSTextInputClient, NSUserInterfaceValidations>
 {
 @private
   ScintillaView* mOwner;