diff --git a/lib/kamerling/registration.rb b/lib/kamerling/registration.rb
index <HASH>..<HASH> 100644
--- a/lib/kamerling/registration.rb
+++ b/lib/kamerling/registration.rb
@@ -4,5 +4,5 @@ require_relative 'project'
 require_relative 'uuid_entity'
 
 module Kamerling class Registration < UUIDEntity
-  attrs addr: Addr, client: Client, project: Project
+  attrs addr: Addr, client: Client, project: Project, registered_at: Time
 end end
diff --git a/spec/kamerling/mapper_spec.rb b/spec/kamerling/mapper_spec.rb
index <HASH>..<HASH> 100644
--- a/spec/kamerling/mapper_spec.rb
+++ b/spec/kamerling/mapper_spec.rb
@@ -45,10 +45,13 @@ module Kamerling describe Mapper do
     end
 
     it 'returns the proper Hash representation of a Registration' do
-      reg = Registration.new addr: addr, client: client, project: project
+      registered_at = Time.new(2014, 7, 6, 5, 4, 3)
+      reg = Registration.new addr: addr, client: client, project: project,
+                             registered_at: registered_at
       Mapper.to_h(reg).must_equal client_uuid: client.uuid, host: '127.0.0.1',
                                   port: 1979, prot: 'TCP',
-                                  project_uuid: project.uuid, uuid: reg.uuid
+                                  project_uuid: project.uuid,
+                                  registered_at: registered_at, uuid: reg.uuid
     end
 
     it 'returns the proper Hash representation of a Result' do
track and persist Registration#registered_at