diff --git a/src/gtkutil.c b/src/gtkutil.c
index f2018bc01f5..a6bba096a43 100644
--- a/src/gtkutil.c
+++ b/src/gtkutil.c
@@ -1887,7 +1887,9 @@ xg_free_frame_widgets (struct frame *f)
 
       /* x_free_frame_resources should have taken care of it */
 #ifndef HAVE_PGTK
+#ifdef HAVE_XDBE
       eassert (!FRAME_X_DOUBLE_BUFFERED_P (f));
+#endif
       g_object_unref (FRAME_X_OUTPUT (f)->im_context);
 #endif
       gtk_widget_destroy (FRAME_GTK_OUTER_WIDGET (f));