1 files changed, 1 insertions, 1 deletions
diff --git a/src/Fl_cocoa.mm b/src/Fl_cocoa.mm
index b021de133..f1157a551 100644
--- a/src/Fl_cocoa.mm
+++ b/src/Fl_cocoa.mm
@@ -715,7 +715,7 @@ void Fl::remove_timeout(Fl_Timeout_Handler cb, void* data)
   NSEnumerator *enumerator = [[self childWindows] objectEnumerator];
   id child;
   while ((child = [enumerator nextObject]) != nil) {
-    [child recursivelySendToSubwindows:sel];
+    if ([child isKindOfClass:[FLWindow class]]) [child recursivelySendToSubwindows:sel];
   }
 }