diff --git a/gdk/x11/gdkscreen-x11.c b/gdk/x11/gdkscreen-x11.c
index 19961b52d4..1baf471f31 100644
--- a/gdk/x11/gdkscreen-x11.c
+++ b/gdk/x11/gdkscreen-x11.c
@@ -1096,12 +1096,16 @@ _gdk_x11_screen_set_window_scale (GdkX11Screen *x11_screen,
 				  int scale)
 {
   GList *toplevels, *l;
+  GdkWindow *root;
 
   if (x11_screen->window_scale == scale)
     return;
 
   x11_screen->window_scale = scale;
 
+  root = x11_screen->root_window;
+  GDK_WINDOW_IMPL_X11 (root->impl)->window_scale = scale;
+
   toplevels = gdk_screen_get_toplevel_windows (GDK_SCREEN (x11_screen));
 
   for (l = toplevels; l != NULL; l = l->next)