diff --git a/lib/api/v3/work_packages/form/form_api.rb b/lib/api/v3/work_packages/form/form_api.rb
index 3491395df8..d2b26edf6a 100644
--- a/lib/api/v3/work_packages/form/form_api.rb
+++ b/lib/api/v3/work_packages/form/form_api.rb
@@ -33,23 +33,8 @@ module API
         class FormAPI < Grape::API
           helpers do
             def process_form_request
-              if form_post_request_body
-                form_post_request_body_without_links = form_post_request_body
-                links = form_post_request_body_without_links.delete('_links')
-
-                # enforces availibility validation of lock_version
-                @representer.represented.lock_version = nil
-                @representer.from_json(form_post_request_body_without_links.to_json)
-
-                if links
-                  link_to_object_extractor = ::API::V3::WorkPackages::LinkToObjectExtractor.new
-                  linked_properties = link_to_object_extractor.parse_links(links)
-
-                  @representer.represented.attributes = linked_properties
-                end
-
-                patch_request_valid?
-              end
+              write_work_package_attributes
+              write_request_valid?
 
               error = ::API::Errors::ErrorBase.create(@representer.represented.errors)
 
@@ -61,9 +46,6 @@ module API
               end
             end
 
-            def form_post_request_body
-              env['api.request.body']
-            end
           end
 
           post '/form' do
diff --git a/lib/api/v3/work_packages/work_packages_api.rb b/lib/api/v3/work_packages/work_packages_api.rb
index 827cb8555e..f6692a8f62 100644
--- a/lib/api/v3/work_packages/work_packages_api.rb
+++ b/lib/api/v3/work_packages/work_packages_api.rb
@@ -44,11 +44,29 @@ module API
                 @representer = ::API::V3::WorkPackages::WorkPackageRepresenter.new(work_package, { current_user: current_user }, :activities, :users)
               end
 
-              def patch_request_body
-                env['api.request.input']
+              def write_work_package_attributes
+                if request_body
+                  request_body_without_links = request_body
+                  links = request_body_without_links.delete('_links')
+
+                  # enforces availibility validation of lock_version
+                  @representer.represented.lock_version = nil
+                  @representer.from_json(request_body_without_links.to_json)
+
+                  if links
+                    link_to_object_extractor = ::API::V3::WorkPackages::LinkToObjectExtractor.new
+                    linked_properties = link_to_object_extractor.parse_links(links)
+
+                    @representer.represented.attributes = linked_properties
+                  end
+                end
+              end
+
+              def request_body
+                env['api.request.body']
               end
 
-              def patch_request_valid?
+              def write_request_valid?
                 contract = WorkPackageContract.new(@representer.represented, current_user)
 
                 # Although the contract triggers the ActiveModel validations on
@@ -77,9 +95,7 @@ module API
             end
 
             patch do
-              @representer.represented.lock_version = nil # enforces availibility validation of lock_version
-
-              @representer.from_json(patch_request_body)
+              write_work_package_attributes
 
               send_notifications = !(params.has_key?(:notify) && params[:notify] == 'false')
               update_service = UpdateWorkPackageService.new(current_user,
@@ -87,7 +103,7 @@ module API
                                                             nil,
                                                             send_notifications)
 
-              if patch_request_valid? && update_service.save
+              if write_request_valid? && update_service.save
                 decorate_work_package(@work_package.reload)
                 @representer
               else