diff --git a/progs/xdemos/pbutil.c b/progs/xdemos/pbutil.c
index d0bbd1b0fce..6c340fd7f9e 100644
--- a/progs/xdemos/pbutil.c
+++ b/progs/xdemos/pbutil.c
@@ -393,6 +393,7 @@ CreatePbuffer(Display *dpy, int screen, FBCONFIG config,
       pBuffer = None;
    }
 
+   XSync(dpy, False);
    /* Restore original X error handler */
    (void) XSetErrorHandler(oldHandler);