diff --git a/app/api/repp/nameservers_v1.rb b/app/api/repp/nameservers_v1.rb
index cbc58eece..d653adf7f 100644
--- a/app/api/repp/nameservers_v1.rb
+++ b/app/api/repp/nameservers_v1.rb
@@ -5,10 +5,10 @@ module Repp
     resource 'registrar/nameservers' do
       put '/' do
         params do
-          requires :data, type: Hash do
+          requires :data, type: Hash, allow_blank: false do
             requires :type, type: String, allow_blank: false
             requires :id, type: String, allow_blank: false
-            requires :attributes, type: Hash do
+            requires :attributes, type: Hash, allow_blank: false do
               requires :hostname, type: String, allow_blank: false
               requires :ipv4, type: Array
               requires :ipv6, type: Array
@@ -16,21 +16,28 @@ module Repp
           end
         end
 
-        old_nameserver = current_user.registrar.nameservers.find_by(hostname: params[:data][:id])
-        error!({ errors: [{ title: "Hostname #{params[:data][:id]} does not exist" }] }, 404) unless old_nameserver
+        hostname = params[:data][:id]
 
-        new_nameserver = old_nameserver.dup
-        new_nameserver.hostname = params[:data][:attributes][:hostname]
-        new_nameserver.ipv4 = params[:data][:attributes][:ipv4]
-        new_nameserver.ipv6 = params[:data][:attributes][:ipv6]
+        unless current_user.registrar.nameservers.exists?(hostname: hostname)
+          error!({ errors: [{ title: "Hostname #{hostname} does not exist" }] }, 404)
+        end
 
-        error!({ errors: [{ title: 'Invalid params' }] }, 400) unless new_nameserver.valid?
+        new_attributes = {
+          hostname: params[:data][:attributes][:hostname],
+          ipv4: params[:data][:attributes][:ipv4],
+          ipv6: params[:data][:attributes][:ipv6],
+        }
 
-        current_user.registrar.replace_nameserver(old_nameserver, new_nameserver)
+        begin
+          current_user.registrar.replace_nameservers(hostname, new_attributes)
+        rescue ActiveRecord::RecordInvalid => e
+          error!({ errors: e.record.errors.full_messages.map { |error| { title: error } } }, 400)
+        end
 
         status 200
         @response = { data: { type: 'nameserver',
-                              id: new_nameserver.hostname, attributes: params[:data][:attributes] } }
+                              id: params[:data][:attributes][:hostname],
+                              attributes: params[:data][:attributes] } }
       end
     end
   end
diff --git a/app/models/registrar.rb b/app/models/registrar.rb
index 4bfb191e1..6a10983d2 100644
--- a/app/models/registrar.rb
+++ b/app/models/registrar.rb
@@ -158,12 +158,16 @@ class Registrar < ActiveRecord::Base
     white_ips.api.pluck(:ipv4, :ipv6).flatten.include?(ip)
   end
 
-  def replace_nameserver(old_nameserver, new_nameserver)
+  # Audit log is needed, therefore no raw SQL
+  def replace_nameservers(hostname, new_attributes)
     transaction do
-      nameservers.where(hostname: old_nameserver.hostname).find_each do |nameserver|
-        nameserver.update!(hostname: new_nameserver.hostname,
-                           ipv4: new_nameserver.ipv4,
-                           ipv6: new_nameserver.ipv6) # Audit log is needed, therefore no raw SQL
+      nameservers.where(hostname: hostname).find_each do |original_nameserver|
+        new_nameserver = Nameserver.new
+        new_nameserver.domain = original_nameserver.domain
+        new_nameserver.attributes = new_attributes
+        new_nameserver.save!
+
+        original_nameserver.destroy!
       end
     end
   end
diff --git a/test/fixtures/contacts.yml b/test/fixtures/contacts.yml
index eaf4401b7..fe11968b9 100644
--- a/test/fixtures/contacts.yml
+++ b/test/fixtures/contacts.yml
@@ -42,6 +42,17 @@ acme_ltd:
   code: acme-ltd-001
   auth_info: 720b3c
 
+jack:
+  name: Jack
+  email: jack@inbox.test
+  phone: '+555.555'
+  ident: 1234
+  ident_type: org
+  registrar: goodnames
+  ident_country_code: US
+  code: jack-001
+  auth_info: e2c440
+
 invalid:
   name: any
   code: any
diff --git a/test/fixtures/domains.yml b/test/fixtures/domains.yml
index 7c0844d97..b2b2a24b5 100644
--- a/test/fixtures/domains.yml
+++ b/test/fixtures/domains.yml
@@ -28,6 +28,16 @@ library:
   period: 1
   period_unit: m
 
+metro:
+  name: metro.test
+  name_dirty: metro.test
+  registrar: goodnames
+  registrant: jack
+  transfer_code: 1071ad
+  valid_to: 2010-07-05
+  period: 1
+  period_unit: m
+
 invalid:
   name: invalid.test
   transfer_code: any
diff --git a/test/fixtures/nameservers.yml b/test/fixtures/nameservers.yml
index 870e678ad..a03dc8cc9 100644
--- a/test/fixtures/nameservers.yml
+++ b/test/fixtures/nameservers.yml
@@ -13,3 +13,11 @@ ns2:
   ipv6:
     - 2001:db8::2
   domain: shop
+
+airport_ns1:
+  hostname: ns1.bestnames.test
+  domain: airport
+
+metro_ns1:
+  hostname: ns1.bestnames.test
+  domain: metro
diff --git a/test/integration/api/nameservers/put_test.rb b/test/integration/api/nameservers/put_test.rb
index d048c29fe..034c885b7 100644
--- a/test/integration/api/nameservers/put_test.rb
+++ b/test/integration/api/nameservers/put_test.rb
@@ -1,17 +1,55 @@
 require 'test_helper'
 
 class APINameserversPutTest < ActionDispatch::IntegrationTest
-  def test_replaces_current_registrar_nameservers
+  def setup
+    @registrar = registrars(:bestnames)
+  end
+
+  def test_deletes_old_nameservers
+    previous_nameserver_ids = @registrar.nameservers.where(hostname: 'ns1.bestnames.test').ids
+    request_params = { format: :json, data: { type: 'nameserver', id: 'ns1.bestnames.test',
+                                              attributes: { hostname: 'ns55.bestnames.test' } } }
+
+    put '/repp/v1/registrar/nameservers', request_params, { 'HTTP_AUTHORIZATION' => http_auth_key }
+    refute @registrar.nameservers(true).where(id: previous_nameserver_ids).exists?
+  end
+
+  def test_creates_new_nameservers
+    request_params = { format: :json, data: { type: 'nameserver', id: 'ns1.bestnames.test',
+                                              attributes: { hostname: 'ns55.bestnames.test' } } }
+    put '/repp/v1/registrar/nameservers', request_params, { 'HTTP_AUTHORIZATION' => http_auth_key }
+    assert_equal 2, @registrar.nameservers.where(hostname: 'ns55.bestnames.test').size
+  end
+
+  def test_saves_all_attributes
     request_params = { format: :json, data: { type: 'nameserver', id: 'ns1.bestnames.test',
                                               attributes: { hostname: 'ns55.bestnames.test',
                                                             ipv4: ['192.0.2.55'],
                                                             ipv6: ['2001:db8::55'] } } }
     put '/repp/v1/registrar/nameservers', request_params, { 'HTTP_AUTHORIZATION' => http_auth_key }
 
-    new_nameserver = registrars(:bestnames).nameservers.find_by(hostname: 'ns55.bestnames.test')
-    assert_nil registrars(:bestnames).nameservers.find_by(hostname: 'ns1.bestnames.test')
+    new_nameserver = domains(:shop).nameservers.find_by(hostname: 'ns55.bestnames.test')
     assert_equal ['192.0.2.55'], new_nameserver.ipv4
     assert_equal ['2001:DB8::55'], new_nameserver.ipv6
+  end
+
+  def test_keeps_other_registrar_nameservers_intact
+    request_params = { format: :json, data: { type: 'nameserver', id: 'ns1.bestnames.test',
+                                              attributes: { hostname: 'ns55.bestnames.test' } } }
+
+    other_registrar_nameserver_ids = registrars(:goodnames).nameservers.ids
+    assert other_registrar_nameserver_ids.any?
+    put '/repp/v1/registrar/nameservers', request_params, { 'HTTP_AUTHORIZATION' => http_auth_key }
+    assert_equal other_registrar_nameserver_ids, registrars(:goodnames).nameservers(true).ids
+  end
+
+  def test_returns_new_nameserver_record
+    request_params = { format: :json, data: { type: 'nameserver', id: 'ns1.bestnames.test',
+                                              attributes: { hostname: 'ns55.bestnames.test',
+                                                            ipv4: ['192.0.2.55'],
+                                                            ipv6: ['2001:db8::55'] } } }
+    put '/repp/v1/registrar/nameservers', request_params, { 'HTTP_AUTHORIZATION' => http_auth_key }
+
     assert_response 200
     assert_equal ({ data: { type: 'nameserver',
                             id: 'ns55.bestnames.test',
@@ -21,7 +59,7 @@ class APINameserversPutTest < ActionDispatch::IntegrationTest
                  JSON.parse(response.body, symbolize_names: true)
   end
 
-  def test_honors_optional_params
+  def test_optional_params
     request_params = { format: :json, data: { type: 'nameserver', id: 'ns1.bestnames.test',
                                               attributes: { hostname: 'ns55.bestnames.test' } } }
     put '/repp/v1/registrar/nameservers', request_params, { 'HTTP_AUTHORIZATION' => http_auth_key }
@@ -44,7 +82,7 @@ class APINameserversPutTest < ActionDispatch::IntegrationTest
     put '/repp/v1/registrar/nameservers', request_params, { 'HTTP_AUTHORIZATION' => http_auth_key }
 
     assert_response 400
-    assert_equal ({ errors: [{ title: 'Invalid params' }] }),
+    assert_equal ({ errors: [{ title: 'Hostname is missing' }] }),
                  JSON.parse(response.body, symbolize_names: true)
   end