diff --git a/app/models/work_package.rb b/app/models/work_package.rb
index 7b5157312a..6e51d35a44 100644
--- a/app/models/work_package.rb
+++ b/app/models/work_package.rb
@@ -178,16 +178,6 @@ class WorkPackage < ActiveRecord::Base
                                        },
                                        method(:cleanup_time_entries_before_destruction_of)
 
-  # Mapping attributes, that are passed in as id's onto their respective associations
-  # (eg. type=4711 onto type=::Type.find(4711))
-  include AssociationsMapper
-  # recovered this from planning-element: is it still needed?!
-  map_associations_for :parent,
-                       :status,
-                       :type,
-                       :project,
-                       :priority
-
   acts_as_journalized except: ['root_id']
 
   # This one is here only to ease reading
diff --git a/lib/associations_mapper.rb b/lib/associations_mapper.rb
deleted file mode 100644
index c4a52f3c00..0000000000
--- a/lib/associations_mapper.rb
+++ /dev/null
@@ -1,78 +0,0 @@
-#-- copyright
-# OpenProject is a project management system.
-# Copyright (C) 2012-2015 the OpenProject Foundation (OPF)
-#
-# 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 doc/COPYRIGHT.rdoc for more details.
-#++
-
-module AssociationsMapper
-  def self.included(base)
-    base.extend(ClassMethods)
-  end
-
-  module ClassMethods
-    # this allows you to set project=4711. which then dos a lookup
-    def map_associations_for(*association_names)
-      association_names.each do |association_name|
-        if reflection = reflect_on_association(association_name)
-          class_eval %{
-            def #{association_name}_with_map_associations_for=(new_value)
-              if new_value.present? && new_value.is_a?(Hash) && new_value.has_key?(:id)
-                obj = #{reflection.klass.name}.find_by(id: new_value[:id])
-
-                if obj.present?
-                  self.#{association_name}_without_accepts_nested_attributes_for_apis = obj
-                else
-                  @errors_in_nested_attributes ||= {}
-                  @errors_in_nested_attributes[:#{association_name}] = [:invalid]
-                end
-              else
-                self.#{association_name}_without_map_associations_for = new_value
-              end
-            end
-            alias_method_chain :#{association_name}=, :map_associations_for
-
-
-          }, __FILE__, __LINE__
-        else
-          raise ArgumentError, "No association found for name `#{association_name}'. Has it been defined yet?"
-        end
-      end
-      include Validations
-    end
-  end
-
-  module Validations
-    def validate
-      if @errors_in_nested_attributes.present?
-        @errors_in_nested_attributes.each do |attribute, errs|
-          errs.each do |error|
-            errors.add attribute, error
-          end
-        end
-      end
-      super
-    end
-  end
-end