diff --git a/lib/slack.js b/lib/slack.js
index 659ba5a0..0fa2e7ec 100644
--- a/lib/slack.js
+++ b/lib/slack.js
@@ -203,7 +203,7 @@ function Slack(opts, debug) {
       var form = r.form();
       form.append('name', alias);
       form.append('mode', 'alias');
-      form.append('alias', name);
+      form.append('alias_for', name);
       form.append('token', opts.apiToken);
     }.bind(this));
   };