diff --git a/lib/overhead_time_entry_activity_patch.rb b/lib/overhead_time_entry_activity_patch.rb
index 13e3732..be48862 100644
--- a/lib/overhead_time_entry_activity_patch.rb
+++ b/lib/overhead_time_entry_activity_patch.rb
@@ -23,6 +23,22 @@ module OverheadTimeEntryActivityPatch
     def overhead_configured?
       Setting['plugin_redmine_overhead'] && Setting['plugin_redmine_overhead']['custom_field']
     end
+
+    def find_with_billable_values(values = [])
+      return [] unless overhead_configured?
+
+      billable_field = TimeEntryActivity.billable_custom_field
+      if billable_field
+        finder = ARCondition.new
+        finder.add "#{CustomValue.table_name}.customized_type = '#{TimeEntryActivity.class_name}'"
+        finder.add ["#{CustomValue.table_name}.custom_field_id = ?", billable_field.id]
+        finder.add ["#{CustomValue.table_name}.value IN (?)", values]
+        
+        return TimeEntryActivity.find(:all, :include => :custom_values, :conditions => finder.conditions)
+      else
+        return []
+      end
+    end
   end
   
   module InstanceMethods
diff --git a/lib/overhead_timesheet_hook.rb b/lib/overhead_timesheet_hook.rb
index ecac969..5c76476 100644
--- a/lib/overhead_timesheet_hook.rb
+++ b/lib/overhead_timesheet_hook.rb
@@ -41,4 +41,11 @@ class OverheadTimesheetHook < Redmine::Hook::ViewListener
                                 :selected_values => selected_values
                               })
   end
+
+  def plugin_timesheet_controller_report_pre_fetch_time_entries(context = {})
+    if context[:params] && context[:params][:timesheet] && context[:params][:timesheet][:billable]
+      activities = TimeEntryActivity.find_with_billable_values(context[:params][:timesheet][:billable])
+      context[:timesheet].activities = activities.collect(&:id) unless activities.empty?
+    end
+  end
 end
diff --git a/spec/lib/overhead_time_entry_activity_patch_spec.rb b/spec/lib/overhead_time_entry_activity_patch_spec.rb
index 2e9bdef..ca048c0 100644
--- a/spec/lib/overhead_time_entry_activity_patch_spec.rb
+++ b/spec/lib/overhead_time_entry_activity_patch_spec.rb
@@ -95,3 +95,26 @@ describe TimeEntryActivity, '#billable_custom_field' do
     end
   end
 end
+
+describe TimeEntryActivity, '#find_with_billable_values' do
+  before(:each) do
+    TimeEntryActivity.stub!(:overhead_configured?).and_return(true)
+  end
+
+  it 'should return nothing if none are found' do
+    TimeEntryActivity.find_with_billable_values.should be_empty
+  end
+
+  it 'should return the time entry activities with the specified billable value' do
+    custom_field = mock_model(TimeEntryActivityCustomField,
+                               :possible_values => ['A','B','Nil'],
+                               :field_format => 'list')
+    TimeEntryActivity.stub!(:billable_custom_field).and_return(custom_field)
+
+    activities = [mock_model(TimeEntryActivity), mock_model(TimeEntryActivity)]
+    TimeEntryActivity.should_receive(:find).and_return(activities)
+    
+    response = TimeEntryActivity.find_with_billable_values(['A','B'])
+    response.should eql(activities)
+  end
+end
diff --git a/spec/lib/overhead_timesheet_hook_spec.rb b/spec/lib/overhead_timesheet_hook_spec.rb
index 5456b38..27406b8 100644
--- a/spec/lib/overhead_timesheet_hook_spec.rb
+++ b/spec/lib/overhead_timesheet_hook_spec.rb
@@ -96,3 +96,47 @@ describe OverheadTimesheetHook, "#plugin_timesheet_views_timesheet_form", :type
     
   end
 end
+
+describe OverheadTimesheetHook, "#plugin_timesheet_controller_report_pre_fetch_time_entries", :type => :view do
+  include Redmine::Hook::Helper
+
+  before(:each) do
+    stub_view_to_use_controller_instance
+    @timesheet = Timesheet.new
+  end
+  
+  it 'should do nothing to the activity list if no billable values are submitted' do
+    @timesheet.should_not_receive(:activities=)
+    context = {:timesheet => @timesheet}
+    call_hook(:plugin_timesheet_controller_report_pre_fetch_time_entries, context)
+  end
+
+  
+  it 'should change the activity list based on the values submitted' do
+    custom_field = mock_model(TimeEntryActivityCustomField,
+                               :possible_values => ['A','B','Nil'],
+                               :field_format => 'list')
+    TimeEntryActivity.stub!(:billable_custom_field).and_return(custom_field)
+
+    activities = [
+                  mock_model(TimeEntryActivity, :id => 100),
+                  mock_model(TimeEntryActivity, :id => 201),
+                  mock_model(TimeEntryActivity, :id => 342)
+                  ]
+    
+    TimeEntryActivity.should_receive(:find_with_billable_values).with(['A','Nil']).and_return(activities)    
+    
+    @timesheet.should_receive(:activities=).with([100,201,342])
+    context = {
+      :timesheet => @timesheet,
+      :params =>
+      {
+        :timesheet => {
+          :billable => ['A','Nil']
+        }
+      }
+    }
+    call_hook(:plugin_timesheet_controller_report_pre_fetch_time_entries, context)
+
+  end
+end