diff --git a/init.rb b/init.rb
index 8247e8a..c791cb2 100644
--- a/init.rb
+++ b/init.rb
@@ -2,10 +2,12 @@ require 'redmine'
 
 # Patches to the Redmine core.
 require 'dispatcher'
+require 'overhead_deliverable_patch'
 require 'overhead_issue_patch'
 require 'overhead_time_entry_patch'
 require 'overhead_time_entry_activity_patch'
 Dispatcher.to_prepare do
+  Deliverable.send(:include, OverheadDeliverablePatch)
   Issue.send(:include, OverheadIssuePatch)
   TimeEntry.send(:include, OverheadTimeEntryPatch)
   TimeEntryActivity.send(:include, OverheadTimeEntryActivityPatch)
diff --git a/lib/overhead_deliverable_patch.rb b/lib/overhead_deliverable_patch.rb
new file mode 100644
index 0000000..00519fa
--- /dev/null
+++ b/lib/overhead_deliverable_patch.rb
@@ -0,0 +1,26 @@
+require_dependency 'deliverable'
+
+module OverheadDeliverablePatch
+  def self.included(base)
+    base.send(:include, InstanceMethods)
+
+    base.class_eval do
+      unloadable
+    end
+  end
+
+  module InstanceMethods
+    # Cost of time logged to overhead activities
+    def overhead_spent
+      time_logs = issues.collect(&:time_entries).flatten
+
+      return time_logs.collect {|time_entry|
+        if time_entry.billable?
+          0
+        else
+          time_entry.cost
+        end
+      }.sum 
+    end
+  end
+end
diff --git a/spec/lib/overhead_deliverable_patch_spec.rb b/spec/lib/overhead_deliverable_patch_spec.rb
new file mode 100644
index 0000000..4582847
--- /dev/null
+++ b/spec/lib/overhead_deliverable_patch_spec.rb
@@ -0,0 +1,42 @@
+require File.dirname(__FILE__) + '/../spec_helper'
+
+describe Deliverable, '#overhead_spent' do
+  before(:each) do
+    @deliverable = Deliverable.new
+  end
+
+  it 'should equal the product of overhead timelogs by their cost' do
+    issue1 = mock_model(Issue)
+    issue1.stub!(:time_entries).and_return do
+      [
+       mock_model(TimeEntry, :cost => 100.0, :billable? => true),
+       mock_model(TimeEntry, :cost => 200.0, :billable? => false)
+       ]
+    end
+    issue2 = mock_model(Issue)
+    issue2.stub!(:time_entries).and_return do
+      [
+       mock_model(TimeEntry, :cost => 10.0, :billable? => false),
+       mock_model(TimeEntry, :cost => 40.0, :billable? => false)
+       ]
+    end
+    
+    issues = [issue1, issue2]
+    
+    @deliverable.stub!(:issues).and_return(issues)
+    @deliverable.overhead_spent.should eql(250.0)
+  end
+
+  it 'should be 0.0 if there are no issues assigned' do
+    @deliverable.stub!(:issues).and_return([])
+    @deliverable.overhead_spent.should eql(0)
+  end
+
+  it 'should be 0.0 if there are no time entries' do
+    issue1 = mock_model(Issue, :time_entries => [])
+    issue2 = mock_model(Issue, :time_entries => [])
+
+    @deliverable.stub!(:issues).and_return([issue1, issue2])
+    @deliverable.overhead_spent.should eql(0)
+  end
+end