diff --git a/vendor/pace/pace.js b/vendor/pace/pace.js
index 09dd958..cfe31ef 100644
--- a/vendor/pace/pace.js
+++ b/vendor/pace/pace.js
@@ -275,7 +275,9 @@ Bar = (function() {
       this.el = document.createElement('div');
       this.el.className = "pace pace-active";
       document.body.className = document.body.className.replace(/pace-done/g, '');
-      document.body.className += ' pace-running';
+      if (!/pace-running/.test(document.body.className)) {
+        document.body.className += ' pace-running';
+      }
       this.el.innerHTML = '<div class="pace-progress">\n  <div class="pace-progress-inner"></div>\n</div>\n<div class="pace-activity"></div>';
       if (targetElement.firstChild != null) {
         targetElement.insertBefore(this.el, targetElement.firstChild);
@@ -292,7 +294,7 @@ Bar = (function() {
     el.className = el.className.replace('pace-active', '');
     el.className += ' pace-inactive';
     document.body.className = document.body.className.replace('pace-running', '');
-    return document.body.className += ' pace-done';
+    return document.body.className += /pace-done/.test(document.body.className) ? '' : ' pace-done';
   };
 
   Bar.prototype.update = function(prog) {