diff --git a/lib/plugins/acts_as_customizable/lib/acts_as_customizable.rb b/lib/plugins/acts_as_customizable/lib/acts_as_customizable.rb
index 96fdbf8b6..3703a5e65 100644
--- a/lib/plugins/acts_as_customizable/lib/acts_as_customizable.rb
+++ b/lib/plugins/acts_as_customizable/lib/acts_as_customizable.rb
@@ -145,7 +145,9 @@ module Redmine
             end
           end
           self.custom_values = target_custom_values
+          custom_values_changed = custom_values.any?(&:changed?)
           custom_values.each(&:save)
+          touch if persisted? && custom_values_changed
           @custom_field_values_changed = false
           true
         end
diff --git a/test/functional/projects_controller_test.rb b/test/functional/projects_controller_test.rb
index 89bfacee6..5c7b8ff94 100644
--- a/test/functional/projects_controller_test.rb
+++ b/test/functional/projects_controller_test.rb
@@ -976,6 +976,30 @@ class ProjectsControllerTest < Redmine::ControllerTest
     assert_equal ['documents', 'issue_tracking', 'repository'], Project.find(1).enabled_module_names.sort
   end
 
+  def test_update_custom_field_should_update_updated_on
+    @request.session[:user_id] = 2
+    project = Project.find(1)
+    project.update_attribute :updated_on, nil
+    assert_equal 'Stable', project.custom_value_for(3).value
+
+    travel_to Time.current do
+      post(
+        :update,
+        :params => {
+          :id => 1,
+          :project => {
+            :custom_field_values => {'3' => 'Alpha'}
+          }
+        }
+      )
+      assert_redirected_to '/projects/ecookbook/settings'
+      assert_equal 'Successful update.', flash[:notice]
+      project.reload
+      assert_equal 'Alpha', project.custom_value_for(3).value
+      assert_equal Time.current, project.updated_on
+    end
+  end
+
   def test_destroy_leaf_project_without_confirmation_should_show_confirmation
     @request.session[:user_id] = 1 # admin