diff --git a/core/modules/startup.js b/core/modules/startup.js
index 694435514..4827332ad 100755
--- a/core/modules/startup.js
+++ b/core/modules/startup.js
@@ -13,7 +13,7 @@ This is the main application logic for both the client and server
 "use strict";
 
 // Set to `true` to enable performance instrumentation
-var PERFORMANCE_INSTRUMENTATION = true;
+var PERFORMANCE_INSTRUMENTATION = false;
 
 var widget = require("$:/core/modules/widgets/widget.js");