diff --git a/src/gtk/window.cpp b/src/gtk/window.cpp
index 2ff5c94b07..5338cda85b 100644
--- a/src/gtk/window.cpp
+++ b/src/gtk/window.cpp
@@ -5633,6 +5633,8 @@ bool wxWindowGTK::IsTransparentBackgroundSupported(wxString* reason) const
 GdkWindow* wxWindowGTK::GTKFindWindow(GtkWidget* widget)
 {
     GdkWindow* window = gtk_widget_get_window(widget);
+    if (window == NULL)
+        return NULL;
     for (const GList* p = gdk_window_peek_children(window); p; p = p->next)
     {
         window = GDK_WINDOW(p->data);
@@ -5647,6 +5649,8 @@ GdkWindow* wxWindowGTK::GTKFindWindow(GtkWidget* widget)
 void wxWindowGTK::GTKFindWindow(GtkWidget* widget, wxArrayGdkWindows& windows)
 {
     GdkWindow* window = gtk_widget_get_window(widget);
+    if (window == NULL)
+        return;
     for (const GList* p = gdk_window_peek_children(window); p; p = p->next)
     {
         window = GDK_WINDOW(p->data);