diff --git a/src/x11/window-x11.c b/src/x11/window-x11.c
index e57bc8622..4d848c7cc 100644
--- a/src/x11/window-x11.c
+++ b/src/x11/window-x11.c
@@ -2458,8 +2458,8 @@ meta_window_x11_update_input_region (MetaWindow *window)
       else if (n_rects == 1 &&
                (rects[0].x == 0 &&
                 rects[0].y == 0 &&
-                rects[0].width == priv->client_rect.width &&
-                rects[0].height == priv->client_rect.height))
+                rects[0].width == window->buffer_rect.width &&
+                rects[0].height == window->buffer_rect.height))
         {
           /* This is the bounding region case. Keep the
            * region as NULL. */