Index: channels/chan_misdn.c
===================================================================
--- channels/chan_misdn.c	(revision 89318)
+++ channels/chan_misdn.c	(working copy)
@@ -1686,11 +1686,11 @@
 			if (++which > a->n)
 				break;
 		}
-		ast_mutex_unlock(&c->lock);
+		ast_channel_unlock(c);
 	}
 	if (c) {
 		ret = ast_strdup(c->name);
-		ast_mutex_unlock(&c->lock);
+		ast_channel_unlock(c);
 	} else
 		ret = NULL;
 	return ret;