diff --git a/app/models/user.rb b/app/models/user.rb
index aaa43c0..ca05a7b 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -95,18 +95,18 @@ class User < ActiveRecord::Base
 
   validates_presence_of     :login
   validates_presence_of     :email
-  validates_format_of       :login, :with => Profile::IDENTIFIER_FORMAT, :if => (lambda {|user| !user.login.blank?})
+  validates_format_of       :login, :message => _('incorrect format'), :with => Profile::IDENTIFIER_FORMAT, :if => (lambda {|user| !user.login.blank?})
   validates_presence_of     :password,                   :if => :password_required?
   validates_presence_of     :password_confirmation,      :if => :password_required?
-  validates_length_of       :password, :within => 4..40, :if => :password_required?
+  validates_length_of       :password, :message => _('length must be within 4 to 40 characters'), :within => 4..40, :if => :password_required?
   validates_confirmation_of :password,                   :if => :password_required?
-  validates_length_of       :login,    :within => 2..40, :if => (lambda {|user| !user.login.blank?})
-  validates_length_of       :email,    :within => 3..100, :if => (lambda {|user| !user.email.blank?})
-  validates_uniqueness_of   :login, :message => _('login already taken')
-  validates_uniqueness_of   :email, :message => _('email already taken'), :case_sensitive => false, :scope => :environment_id
+  validates_length_of       :login, :message => _('length must be within 2 to 40 characters'), :within => 2..40, :if => (lambda {|user| !user.login.blank?})
+  validates_length_of       :email, :message => _('length must be within 3 to 100 characters'),:within => 3..100, :if => (lambda {|user| !user.email.blank?})
+  validates_uniqueness_of   :login, :case_sensitive => false, :scope => :environment_id
+  validates_uniqueness_of   :email, :case_sensitive => false, :scope => :environment_id
   before_save :encrypt_password
   before_save :normalize_email, if: proc{ |u| u.email.present? }
-  validates_format_of :email, :message => _('incorrect email format'), :with => Noosfero::Constants::EMAIL_FORMAT, :if => (lambda {|user| !user.email.blank?})
+  validates_format_of :email, :message => _('incorrect format'), :with => Noosfero::Constants::EMAIL_FORMAT, :if => (lambda {|user| !user.email.blank?})
 
   validates_inclusion_of :terms_accepted, :in => [ '1' ], :if => lambda { |u| ! u.terms_of_use.blank? }, :message => N_('{fn} must be checked in order to signup.').fix_i18n
 
diff --git a/test/unit/user_test.rb b/test/unit/user_test.rb
index 4551feb..a34502f 100644
--- a/test/unit/user_test.rb
+++ b/test/unit/user_test.rb
@@ -21,6 +21,14 @@ class UserTest < ActiveSupport::TestCase
     end
   end
 
+  def test_should_not_allow_duplicate_login
+    user1 = create_user('new_user', :email => 'new_user1@example.com', :password => 'test', :password_confirmation => 'test')
+    assert !user1.errors[:login].present?
+    user1.save!
+    user2 = new_user(:login => 'new_user')
+    assert user2.errors[:login].present?
+  end
+
   def test_should_require_password
     assert_no_difference 'User.count' do
       u = new_user(:password => nil)
@@ -42,6 +50,13 @@ class UserTest < ActiveSupport::TestCase
     end
   end
 
+  def test_email_format
+    assert_no_difference 'User.count' do
+      u = new_user(:email => 'test.email')
+      assert u.errors[:email].present?
+    end
+  end
+
   def test_should_reset_password
     users(:johndoe).update_attributes(:password => 'new password', :password_confirmation => 'new password')
     assert_equal users(:johndoe), User.authenticate('johndoe', 'new password')
--
libgit2 0.21.2