diff --git a/lib/open_project/backlogs/engine.rb b/lib/open_project/backlogs/engine.rb
index e5e5d208f2..b7c817c0e9 100644
--- a/lib/open_project/backlogs/engine.rb
+++ b/lib/open_project/backlogs/engine.rb
@@ -159,7 +159,7 @@ module OpenProject::Backlogs
                if: -> (*) { represented.backlogs_enabled? }
     end
 
-    extend_api_response(:v3, :work_packages, :form, :work_package_payload) do
+    extend_api_response(:v3, :work_packages, :work_package_payload) do
       property :story_points,
                render_nil: true,
                if: -> (*) { backlogs_enabled? && type.story? }
@@ -196,9 +196,11 @@ module OpenProject::Backlogs
              show_if: -> (*) { represented.project.backlogs_enabled? }
     end
 
-    allow_attribute_update :work_package, :story_points
-    allow_attribute_update :work_package, :remaining_hours do
-      if !model.leaf? && model.changed.include?('remaining_hours')
+    allow_attribute_update :work_package, [:create, :update], :story_points
+    allow_attribute_update :work_package, [:create, :update], :remaining_hours do
+      if !model.new_record? &&
+         !model.leaf? &&
+         model.changed.include?('remaining_hours')
         errors.add :error_readonly, 'remaining_hours'
       end
     end
diff --git a/spec/api/work_packages/create_contract_spec.rb b/spec/api/work_packages/create_contract_spec.rb
new file mode 100644
index 0000000000..155c59dd30
--- /dev/null
+++ b/spec/api/work_packages/create_contract_spec.rb
@@ -0,0 +1,92 @@
+#-- copyright
+# OpenProject Backlogs Plugin
+#
+# Copyright (C)2013-2014 the OpenProject Foundation (OPF)
+# Copyright (C)2011 Stephan Eckardt, Tim Felgentreff, Marnen Laibow-Koser, Sandro Munda
+# Copyright (C)2010-2011 friflaj
+# Copyright (C)2010 Maxime Guilbot, Andrew Vit, Joakim Kolsjö, ibussieres, Daniel Passos, Jason Vasquez, jpic, Emiliano Heyns
+# Copyright (C)2009-2010 Mark Maglana
+# Copyright (C)2009 Joe Heck, Nate Lowrie
+#
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License version 3.
+#
+# OpenProject Backlogs is a derivative work based on ChiliProject Backlogs.
+# The copyright follows:
+# Copyright (C) 2010-2011 - Emiliano Heyns, Mark Maglana, friflaj
+# Copyright (C) 2011 - Jens Ulferts, Gregor Schmidt - Finn GmbH - Berlin, Germany
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See doc/COPYRIGHT.rdoc for more details.
+#++
+
+require 'spec_helper'
+
+describe ::API::V3::WorkPackages::CreateContract do
+  let(:work_package) do
+    FactoryGirl.build(:work_package,
+                      project: project)
+  end
+  let(:member) { FactoryGirl.create(:user,
+                                    member_in_project: project,
+                                    member_through_role: role) }
+  let (:project) { FactoryGirl.create(:project) }
+  let(:current_user) { member }
+  let(:permissions) {
+    [
+      :view_work_packages,
+      :add_work_packages
+    ]
+  }
+  let(:role) { FactoryGirl.create :role, permissions: permissions }
+  let(:changed_values) { [] }
+
+  subject(:contract) { described_class.new(work_package, current_user) }
+
+  before do
+    allow(work_package).to receive(:changed).and_return(changed_values)
+  end
+
+  describe 'story points' do
+    context 'has not changed' do
+      it('is valid') { expect(contract.errors.empty?).to be true }
+    end
+
+    context 'has changed' do
+      let(:changed_values) { ['story_points'] }
+
+      it('is valid') { expect(contract.errors.empty?).to be true }
+    end
+  end
+
+  describe 'remaining hours' do
+    context 'is no parent' do
+      before do
+        contract.validate
+      end
+
+      context 'has not changed' do
+        it('is valid') { expect(contract.errors.empty?).to be true }
+      end
+
+      context 'has changed' do
+        let(:changed_values) { ['remaining_hours'] }
+
+        it('is valid') { expect(contract.errors.empty?).to be true }
+      end
+    end
+  end
+end
diff --git a/spec/api/work_package_contract_spec.rb b/spec/api/work_packages/update_contract_spec.rb
similarity index 98%
rename from spec/api/work_package_contract_spec.rb
rename to spec/api/work_packages/update_contract_spec.rb
index e55c705a85..b20755628f 100644
--- a/spec/api/work_package_contract_spec.rb
+++ b/spec/api/work_packages/update_contract_spec.rb
@@ -28,7 +28,7 @@
 
 require 'spec_helper'
 
-describe ::API::V3::WorkPackages::WorkPackageContract do
+describe ::API::V3::WorkPackages::UpdateContract do
   let(:work_package) do
     FactoryGirl.create(:work_package,
                        done_ratio: 50,