diff --git a/common/lib/xmodule/xmodule/js/src/peergrading/track_changes.coffee b/common/lib/xmodule/xmodule/js/src/peergrading/track_changes.coffee
index 61710917a7..947c1a5187 100644
--- a/common/lib/xmodule/xmodule/js/src/peergrading/track_changes.coffee
+++ b/common/lib/xmodule/xmodule/js/src/peergrading/track_changes.coffee
@@ -54,7 +54,7 @@ class @TrackChanges
     keyOfLatestChange = 0
     @tracked_changes = @$(@tracked_changes_sel)
     @tracked_changes.each ->
-      key = parseInt($(@).attr('data-cid'))
+      key = $(@).data('cid')
       if key > keyOfLatestChange
         keyOfLatestChange = key
     @tracker.rejectChange('[data-cid="'+ keyOfLatestChange + '"]')