diff --git a/app/models/dnskey.rb b/app/models/dnskey.rb
index e9e15802f..348bddde7 100644
--- a/app/models/dnskey.rb
+++ b/app/models/dnskey.rb
@@ -34,9 +34,12 @@ class Dnskey < ApplicationRecord
   def epp_code_map
     {
       '2005' => [
-        [:alg, :invalid, { value: { obj: 'alg', val: alg }, values: ALGORITHMS.join(', ') }],
-        [:protocol, :invalid, { value: { obj: 'protocol', val: protocol }, values: PROTOCOLS.join(', ') }],
-        [:flags, :invalid, { value: { obj: 'flags', val: flags }, values: FLAGS.join(', ') }]
+        [:alg, :invalid, { value: { obj: 'alg', val: alg },
+                           values: "Valid algorithms are: #{ALGORITHMS.join(', ')}" }],
+        [:protocol, :invalid, { value: { obj: 'protocol', val: protocol },
+                                values: "Valid protocols are: #{PROTOCOLS.join(', ')}" }],
+        [:flags, :invalid, { value: { obj: 'flags', val: flags },
+                             values: "Valid protocols are: #{PROTOCOLS.join(', ')}" }],
       ],
       '2302' => [
         [:public_key, :taken, { value: { obj: 'pubKey', val: public_key } }]
diff --git a/config/locales/en.yml b/config/locales/en.yml
index a28d97f81..8ba570e6c 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -123,7 +123,7 @@ en:
         dnskey:
           attributes:
             alg:
-              invalid: 'Valid algorithms are: %{values}'
+              invalid: '%{values}'
               blank: 'Algorithm is missing'
             protocol:
               invalid: 'Valid protocols are: %{values}'
diff --git a/test/integration/epp/domain/update/base_test.rb b/test/integration/epp/domain/update/base_test.rb
index 0fb0a5fff..54f817c94 100644
--- a/test/integration/epp/domain/update/base_test.rb
+++ b/test/integration/epp/domain/update/base_test.rb
@@ -17,6 +17,37 @@ class EppDomainUpdateBaseTest < EppTestCase
       @original_registrant_change_verification
   end
 
+  def test_update_dnskey_with_invalid_alg
+    request_xml = <<~XML
+            <?xml version="1.0" encoding="UTF-8" standalone="no"?>
+            <epp xmlns="#{Xsd::Schema.filename(for_prefix: 'epp-ee')}">
+              <command>
+                <update>
+                  <domain:update xmlns:domain="#{Xsd::Schema.filename(for_prefix: 'domain-ee')}">
+                    <domain:name>shop.test</domain:name>
+                  </domain:update>
+                </update>
+      <extension>
+            <secDNS:update xmlns:secDNS="urn:ietf:params:xml:ns:secDNS-1.1">
+              <secDNS:add><secDNS:keyData>
+      	  <secDNS:flags>257</secDNS:flags>
+      	  <secDNS:protocol>3</secDNS:protocol>
+      	  <secDNS:alg>666</secDNS:alg>
+      	  <secDNS:pubKey>P25MwGXr2sTbxdOIKRNbSC8bUO2CObo4/T8kMFoKcgs=</secDNS:pubKey>
+      	</secDNS:keyData></secDNS:add>
+            </secDNS:update>
+          </extension>
+              </command>
+            </epp>
+    XML
+
+    post epp_update_path, params: { frame: request_xml },
+         headers: { 'HTTP_COOKIE' => 'session=api_bestnames' }
+    response_xml = Nokogiri::XML(response.body)
+    assert_correct_against_schema response_xml
+    assert_epp_response :parameter_value_syntax_error
+  end
+
   def test_update_domain
     request_xml = <<-XML
       <?xml version="1.0" encoding="UTF-8" standalone="no"?>