diff --git a/lib/api/v3/custom_fields/hierarchy/hierarchy_item_representer.rb b/lib/api/v3/custom_fields/hierarchy/hierarchy_item_representer.rb
new file mode 100644
index 000000000000..bf1c63b26e25
--- /dev/null
+++ b/lib/api/v3/custom_fields/hierarchy/hierarchy_item_representer.rb
@@ -0,0 +1,43 @@
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# 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 is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# 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 COPYRIGHT and LICENSE files for more details.
+#++
+
+module API
+  module V3
+    module CustomFields
+      module Hierarchy
+        class HierarchyItemRepresenter < ::API::Decorators::Single
+          def _type
+            "HierarchyItem"
+          end
+
+          property :id
+        end
+      end
+    end
+  end
+end
diff --git a/lib/api/v3/utilities/custom_field_injector.rb b/lib/api/v3/utilities/custom_field_injector.rb
index 8cb34ef32e45..55cfa7a52728 100644
--- a/lib/api/v3/utilities/custom_field_injector.rb
+++ b/lib/api/v3/utilities/custom_field_injector.rb
@@ -58,7 +58,7 @@ class CustomFieldInjector
           "user" => "::API::V3::Principals::PrincipalRepresenterFactory",
           "version" => "::API::V3::Versions::VersionRepresenter",
           "list" => "::API::V3::CustomOptions::CustomOptionRepresenter",
-          "hierarchy" => "::API::V3::HierarchyItems::HierarchyItemRepresenter"
+          "hierarchy" => "::API::V3::CustomFields::Hierarchy::HierarchyItemRepresenter"
         }.freeze
 
         class << self