diff --git a/include/wx/gtk/collpane.h b/include/wx/gtk/collpane.h
index 813daea8f4..78c4f26648 100644
--- a/include/wx/gtk/collpane.h
+++ b/include/wx/gtk/collpane.h
@@ -71,6 +71,7 @@ public:     // used by GTK callbacks
 private:
     void OnSize(wxSizeEvent&);
     virtual void AddChildGTK(wxWindowGTK* child);
+    GdkWindow *GTKGetWindow(wxArrayGdkWindows& windows) const;
 
     DECLARE_DYNAMIC_CLASS(wxCollapsiblePane)
     DECLARE_EVENT_TABLE()
diff --git a/src/gtk/collpane.cpp b/src/gtk/collpane.cpp
index ec04fb67f2..b973170e12 100644
--- a/src/gtk/collpane.cpp
+++ b/src/gtk/collpane.cpp
@@ -200,6 +200,15 @@ wxSize wxCollapsiblePane::DoGetBestSize() const
     return sz;
 }
 
+GdkWindow *wxCollapsiblePane::GTKGetWindow(wxArrayGdkWindows& windows) const
+{
+    GtkWidget *label = gtk_expander_get_label_widget( GTK_EXPANDER(m_widget) );
+    windows.Add( label->window );
+    windows.Add( m_widget->window );
+    
+    return NULL;
+}
+
 void wxCollapsiblePane::Collapse(bool collapse)
 {
     // optimization