diff --git a/app/models/user.rb b/app/models/user.rb
index d387dbb..e2d869a 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -119,7 +119,8 @@ class User < ActiveRecord::Base
   # Authenticates a user by their login name and unencrypted password.  Returns the user or nil.
   def self.authenticate(login, password, environment = nil)
     environment ||= Environment.default
-    u = first :conditions => ['login = ? AND environment_id = ? AND activated_at IS NOT NULL', login, environment.id] # need to get the salt
+    u = self.first :conditions => ['(login = ? OR email = ?) AND environment_id = ? AND activated_at IS NOT NULL',
+                                   login, login, environment.id] # need to get the salt
     u && u.authenticated?(password) ? u : nil
   end
 
diff --git a/app/views/account/_signup_form.rhtml b/app/views/account/_signup_form.rhtml
index 560be5b..f18f56f 100644
--- a/app/views/account/_signup_form.rhtml
+++ b/app/views/account/_signup_form.rhtml
@@ -13,7 +13,8 @@
     <span id="signup-domain"><%= environment.default_hostname %>/</span>
     <div id='signup-login'>
       <div id='signup-login-field' class='formfield'>
-        <%= required text_field(:user, :login, :id => 'user_login', :onchange => 'this.value = convToValidLogin(this.value);') %>
+        <%= required text_field(:user, :login, :id => 'user_login',
+                                :onchange => 'this.value = convToValidUsername(this.value);') %>
         <div id='url-check'><p>&nbsp;</p></div>
       </div>
       <%= content_tag(:small, _('Choose your login name carefully! It will be your network access and you will not be able to change it later.'), :id => 'signup-balloon') %>
diff --git a/app/views/account/forgot_password.rhtml b/app/views/account/forgot_password.rhtml
index 537c9f4..1e3748d 100644
--- a/app/views/account/forgot_password.rhtml
+++ b/app/views/account/forgot_password.rhtml
@@ -5,7 +5,7 @@
 <% labelled_form_for :change_password, @change_password, :url => { :action => 'forgot_password' } do |f| %>
 
   <%= f.text_field :login,
-                   :onchange => 'this.value = convToValidLogin( this.value )' %>
+                   :onchange => 'this.value = convToValidUsername( this.value )' %>
 
   <%= f.text_field :email %>
 
diff --git a/public/javascripts/application.js b/public/javascripts/application.js
index 9c271ee..f2a16b9 100644
--- a/public/javascripts/application.js
+++ b/public/javascripts/application.js
@@ -29,7 +29,14 @@ function focus_first_field() {
 
 /* * * Convert a string to a valid login name * * */
 function convToValidLogin( str ) {
-  return convToValidIdentifier(str, '')
+  if (str.indexOf('@') == -1)
+    return convToValidUsername(str);
+  else
+    return convToValidEmail(str);
+}
+
+function convToValidUsername( str ) {
+  return convToValidIdentifier(str, '');
 }
 
 /* * * Convert a string to a valid login name * * */
@@ -46,6 +53,18 @@ function convToValidIdentifier( str, sep ) {
             .replace( /[^-_a-z0-9.]+/g, sep )
 }
 
+function convToValidEmail( str ) {
+  return str.toLowerCase()
+            .replace( /á|à|ã|â/g, "a" )
+            .replace( /é|ê/g,     "e" )
+            .replace( /í/g,       "i" )
+            .replace( /ó|ô|õ|ö/g, "o" )
+            .replace( /ú|ũ|ü/g,   "u" )
+            .replace( /ñ/g,       "n" )
+            .replace( /ç/g,       "c" )
+            .replace( /[^@a-z0-9!#$%&'*+-/=?^_`{|}~.]+/g, '' )
+}
+
 function updateUrlField(name_field, id) {
    url_field = $(id);
    old_url_value = url_field.value;
diff --git a/test/unit/user_test.rb b/test/unit/user_test.rb
index 69fe1a5..833c293 100644
--- a/test/unit/user_test.rb
+++ b/test/unit/user_test.rb
@@ -53,6 +53,8 @@ class UserTest < ActiveSupport::TestCase
 
   def test_should_authenticate_user
     assert_equal users(:johndoe), User.authenticate('johndoe', 'test')
+    assert_equal users(:johndoe), User.authenticate('johndoe@localhost.localdomain', 'test')
+    assert_equal nil, User.authenticate('wrongemail@localhost', 'test')
   end
 
   def test_should_authenticate_user_of_nondefault_environment
--
libgit2 0.21.2