diff --git a/src/mac/carbon/toplevel.cpp b/src/mac/carbon/toplevel.cpp
index 8d279e9599..6a5284d6da 100644
--- a/src/mac/carbon/toplevel.cpp
+++ b/src/mac/carbon/toplevel.cpp
@@ -1173,6 +1173,11 @@ void  wxTopLevelWindowMac::MacCreateRealWindow(
 
     wxCHECK_RET( err == noErr, wxT("Mac OS error when trying to create new window") );
 
+    // setup a separate group for each window, so that overlays can be handled easily
+    verify_noerr( CreateWindowGroup( kWindowGroupAttrMoveTogether | kWindowGroupAttrLayerTogether | kWindowGroupAttrHideOnCollapse, &group ));
+    verify_noerr( SetWindowGroupParent( group, GetWindowGroup( (WindowRef) m_macWindow )));
+    verify_noerr( SetWindowGroup( (WindowRef) m_macWindow , group ));
+  
     // the create commands are only for content rect,
     // so we have to set the size again as structure bounds
     SetWindowBounds(  (WindowRef) m_macWindow , kWindowStructureRgn , &theBoundsRect ) ;