--- macosx/tkMacOSXWindowEvent.c.orig	2025-07-26 14:20:28.000000000 +0100
+++ macosx/tkMacOSXWindowEvent.c	2025-07-26 14:24:11.000000000 +0100
@@ -977,8 +977,11 @@
 	self.layer = [CALayer layer];
 	self.wantsLayer = YES;
 	self.layerContentsRedrawPolicy = NSViewLayerContentsRedrawOnSetNeedsDisplay;
-	self.layer.contentsGravity = self.layer.contentsAreFlipped ?
-	    kCAGravityTopLeft : kCAGravityBottomLeft;
+	if (self.layer.contentsAreFlipped) {
+	    self.layer.contentsGravity = kCAGravityTopLeft;
+	} else {
+	    self.layer.contentsGravity = kCAGravityBottomLeft;
+	}
 
 	/*
 	 * Nothing gets drawn at all if the layer does not have a delegate.

