diff --git a/app/models/user.rb b/app/models/user.rb
index 0696a8da1..47d5eb24a 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -506,7 +506,7 @@ class User < ActiveRecord::Base
     end
 
     def email_validator
-      if (setting = SiteSetting.email_domains_blacklist).present?
+      if new_record? and (setting = SiteSetting.email_domains_blacklist).present?
         domains = setting.gsub('.', '\.')
         regexp = Regexp.new("@(#{domains})", true)
         if self.email =~ regexp
diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index a5174b503..a8b740340 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -478,6 +478,12 @@ describe User do
       SiteSetting.stubs(:email_domains_blacklist).returns('trashmail.net')
       Fabricate.build(:user, email: 'good@trashmailinet.com').should be_valid
     end
+
+    it 'should not be used to validate existing records' do
+      u = Fabricate(:user, email: 'in_before_blacklisted@fakemail.com')
+      SiteSetting.stubs(:email_domains_blacklist).returns('fakemail.com')
+      u.should be_valid
+    end
   end
 
   describe 'passwords' do