--- dwm.c
+++ dwm.c
@@ -723,6 +790,9 @@ destroynotify(XEvent *e)
 
 	if ((c = wintoclient(ev->window)))
 		unmanage(c, 1);
+
+	else if ((c = swallowingclient(ev->window)))
+		unmanage(c->swallowing, 1);
 }
 
 void