diff --git a/lib/devise/models/validatable.rb b/lib/devise/models/validatable.rb
index e18d2d9b..11b28176 100644
--- a/lib/devise/models/validatable.rb
+++ b/lib/devise/models/validatable.rb
@@ -12,14 +12,18 @@ module Devise
 
       def self.included(base)
         base.class_eval do
+          attribute = authentication_keys.first
 
-          validates_presence_of     :email
-          validates_uniqueness_of   :email, :allow_blank => true
-          validates_format_of       :email, :with => EMAIL_REGEX, :allow_blank => true
+          validates_presence_of   attribute
+          validates_uniqueness_of attribute, :allow_blank => true
+          validates_format_of     attribute, :with => EMAIL_REGEX, :allow_blank => true,
+                                              :scope => authentication_keys[1..-1]
 
-          validates_presence_of     :password, :if => :password_required?
-          validates_confirmation_of :password, :if => :password_required?
-          validates_length_of       :password, :within => 6..20, :allow_blank => true, :if => :password_required?
+          with_options :if => :password_required? do |v|
+            v.validates_presence_of     :password
+            v.validates_confirmation_of :password
+            v.validates_length_of       :password, :within => 6..20, :allow_blank => true
+          end
         end
       end