diff --git a/src/plugins/platforms/cocoa/qnswindow.h b/src/plugins/platforms/cocoa/qnswindow.h
index ea690b69e3d..64f1ed08026 100644
--- a/src/plugins/platforms/cocoa/qnswindow.h
+++ b/src/plugins/platforms/cocoa/qnswindow.h
@@ -67,6 +67,7 @@ QT_FORWARD_DECLARE_CLASS(QCocoaWindow)
 - (void)dealloc;
 - (BOOL)isOpaque;
 - (NSColor *)backgroundColor;
+- (NSString *)description;
 @property (nonatomic, readonly) QCocoaWindow *platformWindow;
 @end