diff --git a/lib/overhead_time_entry_activity_patch.rb b/lib/overhead_time_entry_activity_patch.rb
index 2fa454d..7a912f9 100644
--- a/lib/overhead_time_entry_activity_patch.rb
+++ b/lib/overhead_time_entry_activity_patch.rb
@@ -39,6 +39,7 @@ module OverheadTimeEntryActivityPatch
       return false unless field
       
       custom_value = self.custom_value_for(field)
+      return false unless custom_value
       
       if field.field_format == 'bool'
         # Map string values to proper booleans
diff --git a/lib/overhead_timesheet_hook.rb b/lib/overhead_timesheet_hook.rb
index 22f5e67..12481af 100644
--- a/lib/overhead_timesheet_hook.rb
+++ b/lib/overhead_timesheet_hook.rb
@@ -3,4 +3,13 @@ class OverheadTimesheetHook < Redmine::Hook::ViewListener
   def plugin_timesheet_views_timesheet_group_header(context={})
     return content_tag(:th, l(:overhead_field_billable))
   end
+
+  def plugin_timesheet_views_timesheet_time_entry(context={})
+    time_entry = context[:time_entry]
+    if time_entry && time_entry.billable? 
+      content_tag(:td, image_tag('true.png'))
+    else 
+      content_tag(:td,'') 
+    end 
+  end
 end
diff --git a/spec/lib/overhead_timesheet_hook_spec.rb b/spec/lib/overhead_timesheet_hook_spec.rb
index 39b097a..d23aa67 100644
--- a/spec/lib/overhead_timesheet_hook_spec.rb
+++ b/spec/lib/overhead_timesheet_hook_spec.rb
@@ -5,3 +5,32 @@ describe OverheadTimesheetHook, "#plugin_timesheet_views_timesheet_group_header"
     OverheadTimesheetHook.instance.plugin_timesheet_views_timesheet_group_header.should eql('<th>Billable</th>')
   end
 end
+
+describe OverheadTimesheetHook, "#plugin_timesheet_views_timesheet_time_entry" do
+  before(:each) do
+  end
+
+  def call_hook(time_entry)
+    context = {:time_entry => time_entry}
+    return OverheadTimesheetHook.instance.plugin_timesheet_views_timesheet_time_entry(context)
+  end
+
+  it 'should add a table cell' do
+    time_entry = mock_model(TimeEntry, :billable? => false)
+    call_hook(time_entry).should have_tag('td')
+  end
+
+  it "should be an empty cell if a time entry isn't billable" do
+    time_entry = mock_model(TimeEntry)
+    time_entry.should_receive(:billable?).and_return(false)
+    call_hook(time_entry).should have_tag('td','')
+  end
+
+  it "should have a checkbox if a time entry is billable" do
+    time_entry = mock_model(TimeEntry)
+    time_entry.should_receive(:billable?).and_return(true)
+    call_hook(time_entry).should have_tag('td') do
+      with_tag('img[src*=?]','true.png')
+    end
+  end
+end