diff --git a/app/views/graders/_grader.html.haml b/app/views/graders/_grader.html.haml
--- a/app/views/graders/_grader.html.haml
+++ b/app/views/graders/_grader.html.haml
@@ -2,10 +2,10 @@
 %td= grader.host
 %td= grader.pid
 %td= grader.mode
-%td= grader.updated_at.strftime("%H:%M:%S") if grader.updated_at!=nil
+%td= grader.updated_at.strftime("%H:%M:%S") unless grader.updated_at.nil?
 %td= grader.task_type
 %td
-  - if grader.task_id==nil
+  - if grader.task_id.nil?
     idle
   - else
     = link_to "#{grader.task_id}", :action => 'view', :id => grader.task_id, :type => grader.task_type