diff --git a/lib/redmine/helpers/time_report.rb b/lib/redmine/helpers/time_report.rb
index 89b94ec3c4..1cf4604438 100644
--- a/lib/redmine/helpers/time_report.rb
+++ b/lib/redmine/helpers/time_report.rb
@@ -122,7 +122,7 @@ module Redmine
           'tracker' => {:sql => "#{Issue.table_name}.tracker_id",
                         :klass => Tracker,
                         :label => :label_tracker},
-          'activity' => {:sql => "#{TimeEntry.table_name}.activity_id",
+          'activity' => {:sql => "COALESCE(#{TimeEntryActivity.table_name}.parent_id, #{TimeEntryActivity.table_name}.id)",
                          :klass => TimeEntryActivity,
                          :label => :field_activity},
           'issue' => {:sql => "#{TimeEntry.table_name}.issue_id",
diff --git a/test/functional/timelog_report_test.rb b/test/functional/timelog_report_test.rb
index 19ae055ea7..f8ce54cf40 100644
--- a/test/functional/timelog_report_test.rb
+++ b/test/functional/timelog_report_test.rb
@@ -224,6 +224,19 @@ class TimelogReportTest < Redmine::ControllerTest
     assert_select 'td', :text => 'New'
   end
 
+  def test_report_with_activity_criterion_should_aggregate_by_system_activity_ids
+    activity = TimeEntryActivity.create!(:name => 'Design', :parent_id => 9, :project_id => 3)
+    TimeEntry.generate!(:project_id => 3, :issue_id => 5, :activity_id => activity.id, :spent_on => '2007-05-23', :hours => 10.0)
+
+    get :report, :params => {:project_id => 1, :criteria => ['activity']}
+    assert_response :success
+
+    assert_select 'tr.last-level:first' do
+      assert_select 'td.name', :text => 'Design'
+      assert_select 'td.hours:last', :text => '165.25'
+    end
+  end
+
   def test_report_all_projects_csv_export
     get :report, :params => {
       :columns => 'month',