diff --git a/channels/chan_agent.c b/channels/chan_agent.c
index 29dc13a5ad..d487428e56 100755
--- a/channels/chan_agent.c
+++ b/channels/chan_agent.c
@@ -348,7 +348,9 @@ static int agent_hangup(struct ast_channel *ast)
 	ast_pthread_mutex_unlock(&p->app_lock);
 
 	if (p->pending) {
+		ast_pthread_mutex_lock(&agentlock);
 		agent_unlink(p);
+		ast_pthread_mutex_unlock(&agentlock);
 	}
 	if (p->dead)
 		free(p);