diff --git a/lib/reporters/base.js b/lib/reporters/base.js
index d5425c8a53..172d489785 100644
--- a/lib/reporters/base.js
+++ b/lib/reporters/base.js
@@ -304,7 +304,7 @@ function Base (runner) {
 
   runner.on('end', function () {
     stats.end = new Date();
-    stats.duration = new Date() - stats.start;
+    stats.duration = stats.end - stats.start;
   });
 
   runner.on('pending', function () {