diff --git a/web/assets/javascripts/dashboard.js b/web/assets/javascripts/dashboard.js
index 4132837e..58e53fb9 100644
--- a/web/assets/javascripts/dashboard.js
+++ b/web/assets/javascripts/dashboard.js
@@ -97,7 +97,7 @@ var historyGraph = function() {
 
   var hoverDetail = new Rickshaw.Graph.HoverDetail({
     graph: graph,
-    yFormatter: function(y) { return Math.floor(y) },
+    yFormatter: function(y) { return Math.floor(y).numberWithDelimiter() },
   });
 }