diff --git a/lib/open_project/reporting/engine.rb b/lib/open_project/reporting/engine.rb
index a0b7af7871..4bf5ea9b37 100644
--- a/lib/open_project/reporting/engine.rb
+++ b/lib/open_project/reporting/engine.rb
@@ -90,6 +90,9 @@ module OpenProject::Reporting
       require_dependency 'cost_query/group_by'
     end
 
-    patches [:CostlogController, :TimelogController, :CustomFieldsController]
+    patches [:CostlogController,
+             :TimelogController,
+             :CustomFieldsController,
+             :'OpenProject::Configuration']
   end
 end
diff --git a/lib/open_project/reporting/patches/open_project/configuration_patch.rb b/lib/open_project/reporting/patches/open_project/configuration_patch.rb
new file mode 100644
index 0000000000..60faa865a4
--- /dev/null
+++ b/lib/open_project/reporting/patches/open_project/configuration_patch.rb
@@ -0,0 +1,31 @@
+#-- copyright
+# OpenProject Reporting Plugin
+#
+# Copyright (C) 2010 - 2014 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.
+#
+# 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.
+#++
+
+
+require_dependency 'open_project/configuration'
+
+module OpenProject::Reporting::Patches
+  module OpenProject::ConfigurationPatch
+    def self.included(base)
+      base.class_eval do
+        @defaults['cost_reporting_cache_filter_classes'] = true
+      end
+    end
+  end
+end
diff --git a/spec/lib/open_project/configuration_spec.rb b/spec/lib/open_project/configuration_spec.rb
new file mode 100644
index 0000000000..228cc82973
--- /dev/null
+++ b/spec/lib/open_project/configuration_spec.rb
@@ -0,0 +1,47 @@
+#-- copyright
+# OpenProject Reporting Plugin
+#
+# Copyright (C) 2010 - 2014 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.
+#
+# 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.
+#++
+
+require 'spec_helper'
+
+describe 'OpenProject::Configuration' do
+  context '.cost_reporting_cache_filter_classes' do
+    before do
+      # This prevents the values from the actual configuration file to influence
+      # the test outcome.
+      #
+      # TODO: I propose to port this over to the core to always prevent this for specs.
+      OpenProject::Configuration.load(file: 'bogus')
+    end
+
+    after do
+      # resetting for now to avoid braking specs, who by now rely on having the file read.
+      OpenProject::Configuration.load
+    end
+
+    it 'is a true by default via the method' do
+      expect(OpenProject::Configuration.cost_reporting_cache_filter_classes).to be_truthy
+    end
+
+
+    it 'is true by default via the hash' do
+      expect(OpenProject::Configuration['cost_reporting_cache_filter_classes']).to be_truthy
+    end
+
+  end
+end