diff --git a/include/wx/compositewin.h b/include/wx/compositewin.h
index 8483414686..23ee6f738b 100644
--- a/include/wx/compositewin.h
+++ b/include/wx/compositewin.h
@@ -186,8 +186,21 @@ private:
         // support) to hook into its event processing.
 
         wxWindow *child = event.GetWindow();
-        if ( child == this )
-            return; // not a child, we don't want to bind to ourselves
+
+        // Check that it's one of our children: it could also be this window
+        // itself (for which we don't need to handle focus at all) or one of
+        // its grandchildren and we don't want to bind to those as child
+        // controls are supposed to be well-behaved and get their own focus
+        // event if any of their children get focus anyhow, so binding to them
+        // would only result in duplicate events.
+        //
+        // Notice that we can't use GetCompositeWindowParts() here because the
+        // member variables that are typically used in its implementation in
+        // the derived classes would typically not be initialized yet, as this
+        // event is generated by "m_child = new wxChildControl(this, ...)" code
+        // before "m_child" is assigned.
+        if ( child->GetParent() != this )
+            return;
 
         child->Bind(wxEVT_SET_FOCUS, &wxCompositeWindow::OnSetFocus, this);