diff --git a/app/models/user.rb b/app/models/user.rb
index cdf6592bc69cae6f176e502fdd340fb0b3e17e96..7767d266aa69ae2141b3604f80e4522c06f89aea 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -198,7 +198,7 @@ class User < ActiveRecord::Base
     end
 
     def by_username_or_id(name_or_id)
-      where('users.username = ? OR users.id = ?', name_or_id, name_or_id.to_i).first
+      where('users.username = ? OR users.id = ?', name_or_id.to_s, name_or_id.to_i).first
     end
 
     def build_user(attrs = {}, options= {})