diff --git a/src/common/dcbase.cpp b/src/common/dcbase.cpp
index d3218785be..0d8f069ea6 100644
--- a/src/common/dcbase.cpp
+++ b/src/common/dcbase.cpp
@@ -1349,8 +1349,13 @@ void wxOverlayImpl::BeginDrawing( wxWindowDC* dc)
 {
     delete dc->m_graphicContext ;
     dc->m_graphicContext = new wxMacCGContext( m_overlayContext );
+    // we are right now startin at 0,0 not at the wxWindow's origin, so most of the calculations 
+    // int dc are already corect
+    // just to make sure :
     dc->m_macLocalOrigin.x = 0 ;
     dc->m_macLocalOrigin.y = 0 ;
+    wxSize size = m_window->GetSize() ;
+    dc->SetClippingRegion( 0 , 0 , size.x , size.y ) ;
 }
 
 void wxOverlayImpl::EndDrawing( wxWindowDC* dc)