diff --git a/lib/tasks/sip_refer.js b/lib/tasks/sip_refer.js
index 3dd9fb9b..ea5f0456 100644
--- a/lib/tasks/sip_refer.js
+++ b/lib/tasks/sip_refer.js
@@ -51,6 +51,7 @@ class TaskSipRefer extends Task {
     super.kill(cs);
     const {dlg} = cs;
     dlg.off('notify', this.notifyHandler);
+    this.notifyTaskDone();
   }
 
   async _handleNotify(cs, dlg, req, res) {