diff --git a/src/user.js b/src/user.js
index 390520b5a..c21f933ab 100644
--- a/src/user.js
+++ b/src/user.js
@@ -78,7 +78,7 @@ function validateUsername(username) {
     assert.strictEqual(typeof username, 'string');
     // https://github.com/gogits/gogs/blob/52c8f691630548fe091d30bcfe8164545a05d3d5/models/repo.go#L393
     // admin@fqdn is also reservd for sending emails
-    var RESERVED_USERNAMES = [ 'admin', 'no-reply' ]; // apps like wordpress, gogs don't like these
+    var RESERVED_USERNAMES = [ 'admin', 'no-reply', 'postmaster', 'mailer-daemon' ]; // apps like wordpress, gogs don't like these
 
     // allow empty usernames
     if (username === '') return null;