diff --git a/node-imap/imap-tests.ts b/node-imap/imap-tests.ts
index 61f4b2e0c..3c124ca46 100644
--- a/node-imap/imap-tests.ts
+++ b/node-imap/imap-tests.ts
@@ -1,3 +1,5 @@
+/// <reference path="./imap.d.ts" />
+
 import Imap = require('imap');
 var inspect = require('util').inspect;