diff --git a/app/models/dnskey.rb b/app/models/dnskey.rb
index 59fe57c17..87f44166f 100644
--- a/app/models/dnskey.rb
+++ b/app/models/dnskey.rb
@@ -15,7 +15,7 @@ class Dnskey < ActiveRecord::Base
   def epp_code_map
     {
       '2005' => [
-        [:alg, :invalid, { value: { obj: 'alg', val: alg } }],
+        [:alg, :invalid, { value: { obj: 'alg', val: alg }, values: ALGORITHMS.join(', ') }],
         [:protocol, :invalid, { value: { obj: 'protocol', val: protocol } }],
         [:flags, :invalid, { value: { obj: 'flags', val: flags } }]
       ],
@@ -36,8 +36,8 @@ class Dnskey < ActiveRecord::Base
 
   def validate_algorithm
     return if alg.blank?
-    return if %w(3 5 6 7 8 252 253 254 255).include?(alg.to_s)
-    errors.add(:alg, :invalid)
+    return if ALGORITHMS.include?(alg.to_s)
+    errors.add(:alg, :invalid, values: ALGORITHMS.join(', '))
   end
 
   def validate_protocol
diff --git a/config/locales/en.yml b/config/locales/en.yml
index b51fa2b78..3cb52fb35 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -191,7 +191,7 @@ en:
         dnskey:
           attributes:
             alg:
-              invalid: 'Algorithm is invalid'
+              invalid: 'Valid algorithms are %{values}'
               blank: 'Algorithm is missing'
             protocol:
               invalid: 'Protocol is invalid'
diff --git a/spec/epp/domain_spec.rb b/spec/epp/domain_spec.rb
index f3939cd0a..9974df120 100644
--- a/spec/epp/domain_spec.rb
+++ b/spec/epp/domain_spec.rb
@@ -398,7 +398,7 @@ describe 'EPP Domain', epp: true do
 
         response = epp_request(xml, :xml)
 
-        expect(response[:results][0][:msg]).to eq('Algorithm is invalid')
+        expect(response[:results][0][:msg]).to eq('Valid algorithms are 3, 5, 6, 7, 8, 252, 253, 254, 255')
         expect(response[:results][0][:value]).to eq('9')
 
         expect(response[:results][1][:msg]).to eq('Protocol is invalid')
@@ -407,7 +407,7 @@ describe 'EPP Domain', epp: true do
         expect(response[:results][2][:msg]).to eq('Flag is invalid')
         expect(response[:results][2][:value]).to eq('250')
 
-        expect(response[:results][3][:msg]).to eq('Algorithm is invalid')
+        expect(response[:results][3][:msg]).to eq('Valid algorithms are 3, 5, 6, 7, 8, 252, 253, 254, 255')
         expect(response[:results][3][:value]).to eq('10')
 
         expect(response[:results][4][:msg]).to eq('Flag is invalid')