diff --git a/gdk/macos/GdkMacosGLView.c b/gdk/macos/GdkMacosGLView.c
index 64bd0e89c3..7945184c0b 100644
--- a/gdk/macos/GdkMacosGLView.c
+++ b/gdk/macos/GdkMacosGLView.c
@@ -82,7 +82,9 @@ G_GNUC_BEGIN_IGNORE_DEPRECATIONS
 
 -(BOOL)isOpaque
 {
-  return NO;
+  if ([self window])
+    return [[self window] isOpaque];
+  return YES;
 }
 
 -(BOOL)isFlipped