diff --git a/app/models/user.rb b/app/models/user.rb
index 070125d..9be77e0 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -95,10 +95,8 @@ class User < ActiveRecord::Base
     end
   end
 
-  def self.username_regex
-    User.validators_on(:username).select{|v|
-      v.class == ActiveModel::Validations::FormatValidator }.first.
-      options[:with].inspect
+  def self.username_regex_s
+    "/^" + VALID_USERNAME.to_s.gsub(/(\?-mix:|\(|\))/, "") + "$/"
   end
 
   def as_json(options = {})
diff --git a/app/views/settings/index.html.erb b/app/views/settings/index.html.erb
index 1ac928d..b6c55ee 100644
--- a/app/views/settings/index.html.erb
+++ b/app/views/settings/index.html.erb
@@ -14,7 +14,7 @@
       <%= f.label :username, t('.username'), :class => "required" %>
       <%= f.text_field :username, :size => 15 %>
       <span class="hint">
-        <tt><%= User.username_regex %></tt>
+        <tt><%= User.username_regex_s %></tt>
       </span>
     </div>
 
diff --git a/app/views/signup/invited.html.erb b/app/views/signup/invited.html.erb
index f23f9d2..8ccb84c 100644
--- a/app/views/signup/invited.html.erb
+++ b/app/views/signup/invited.html.erb
@@ -27,7 +27,7 @@
     <%= f.label :username, "Username:", :class => "required" %>
     <%= f.text_field :username, :size => 30 %>
     <span class="hint">
-      <tt><%= User.username_regex %></tt>
+      <tt><%= User.username_regex_s %></tt>
     </span>
     <br />