--- rxvt-unicode/src/command.C	2011/09/01 08:11:26	1.497
+++ rxvt-unicode/src/command.C	2011/09/30 13:31:21	1.498
@@ -1718,6 +1718,7 @@
       h->flags = h->flags & ~XUrgencyHint | (enable ? XUrgencyHint : 0);
       XSetWMHints (dpy, parent, h);
       urgency_hint = enable;
+      XFree (h);
     }
 }
 #endif