diff --git a/app/models/domain.rb b/app/models/domain.rb
index ec632ffaa..2fa4387b3 100644
--- a/app/models/domain.rb
+++ b/app/models/domain.rb
@@ -33,7 +33,7 @@ class Domain < ActiveRecord::Base
   validates :owner_contact, presence: true
 
   validate :validate_period
-  validate :validate_nameservers_uniqueness
+  #validate :validate_nameservers_uniqueness
 
   def name=(value)
     value.strip!
diff --git a/app/models/nameserver.rb b/app/models/nameserver.rb
index c52ba6b1b..b08702a7c 100644
--- a/app/models/nameserver.rb
+++ b/app/models/nameserver.rb
@@ -2,7 +2,7 @@ class Nameserver < ActiveRecord::Base
   include EppErrors
 
   EPP_ATTR_MAP = {
-    hostname: 'hostName'
+    hostname: 'hostObj'
   }
 
   belongs_to :registrar
@@ -12,8 +12,13 @@ class Nameserver < ActiveRecord::Base
   validates :ipv4, format: { with: /\A(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\z/, allow_blank: true }
   validates :ipv6, format: { with: /(([0-9a-fA-F]{1,4}:){7,7}[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,7}:|([0-9a-fA-F]{1,4}:){1,6}:[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,5}(:[0-9a-fA-F]{1,4}){1,2}|([0-9a-fA-F]{1,4}:){1,4}(:[0-9a-fA-F]{1,4}){1,3}|([0-9a-fA-F]{1,4}:){1,3}(:[0-9a-fA-F]{1,4}){1,4}|([0-9a-fA-F]{1,4}:){1,2}(:[0-9a-fA-F]{1,4}){1,5}|[0-9a-fA-F]{1,4}:((:[0-9a-fA-F]{1,4}){1,6})|:((:[0-9a-fA-F]{1,4}){1,7}|:)|fe80:(:[0-9a-fA-F]{0,4}){0,4}%[0-9a-zA-Z]{1,}|::(ffff(:0{1,4}){0,1}:){0,1}((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9]).){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])|([0-9a-fA-F]{1,4}:){1,4}:((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9]).){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9]))/, allow_blank: true }
 
+  validates :hostname, uniqueness: { scope: :domain_id }
+
   def epp_code_map
     {
+      '2302' => [
+        [:hostname, :taken]
+      ],
       '2005' => [
         [:hostname, :invalid],
         [:ipv4, :invalid],
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 275431cb5..d93b6bdaa 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -99,6 +99,7 @@ en:
           attributes:
             hostname:
               invalid: 'Hostname is invalid'
+              taken: 'Nameserver already exists on this domain'
             ipv4:
               invalid: 'IPv4 is invalid'
             ipv6: