diff --git a/lib/tools/phantomas/custom_modules/core/scopeYLT/scopeYLT.js b/lib/tools/phantomas/custom_modules/core/scopeYLT/scopeYLT.js
index c7478bb..5bd80bc 100644
--- a/lib/tools/phantomas/custom_modules/core/scopeYLT/scopeYLT.js
+++ b/lib/tools/phantomas/custom_modules/core/scopeYLT/scopeYLT.js
@@ -42,7 +42,7 @@ exports.module = function(phantomas) {
                             return false;
                         }
 
-                        phantomas.log('Attaching a spy to "' + fn + '" function...');
+                        phantomas.log('Attaching a YLT spy to "' + fn + '" function...');
 
                         obj[fn] = function() {
                             var result;
diff --git a/lib/tools/phantomas/custom_modules/modules/javaScriptBottleYLT/javaScriptBottleYLT.js b/lib/tools/phantomas/custom_modules/modules/javaScriptBottleYLT/javaScriptBottleYLT.js
new file mode 100644
index 0000000..3409c04
--- /dev/null
+++ b/lib/tools/phantomas/custom_modules/modules/javaScriptBottleYLT/javaScriptBottleYLT.js
@@ -0,0 +1,56 @@
+/**
+ * Reports the use of functions known to be serious performance bottlenecks in JS
+ *
+ * @see http://www.nczonline.net/blog/2013/06/25/eval-isnt-evil-just-misunderstood/
+ * @see http://www.quirksmode.org/blog/archives/2005/06/three_javascrip_1.html
+ * @see http://www.stevesouders.com/blog/2012/04/10/dont-docwrite-scripts/
+ */
+/* global document: true, window: true */
+'use strict';
+
+exports.version = '0.1';
+
+exports.module = function(phantomas) {
+    phantomas.setMetric('documentWriteCalls'); //@desc number of calls to either document.write or document.writeln
+    phantomas.setMetric('evalCalls'); // @desc number of calls to eval (either direct or via setTimeout / setInterval)
+
+    phantomas.once('init', function() {
+        phantomas.evaluate(function() {
+            (function(phantomas) {
+                function report(msg, caller, backtrace, metric) {
+                    phantomas.log(msg + ': from ' + caller + '!');
+                    phantomas.log('Backtrace: ' + backtrace);
+                    phantomas.incrMetric(metric);
+                }
+
+                // spy calls to eval()
+                phantomas.spy(window, 'eval', function(code) {
+                    report('eval() called directly', phantomas.getCaller(), phantomas.getBacktrace(), 'evalCalls');
+                    phantomas.log('eval\'ed code: ' + (code || '').substring(0, 150) + '(...)');
+                });
+
+                // spy calls to setTimeout / setInterval with string passed instead of a function
+                phantomas.spy(window, 'setTimeout', function(fn, interval) {
+                    if (typeof fn !== 'string') return;
+
+                    report('eval() called via setTimeout("' + fn + '")', phantomas.getCaller(), phantomas.getBacktrace(), 'evalCalls');
+                });
+
+                phantomas.spy(window, 'setInterval', function(fn, interval) {
+                    if (typeof fn !== 'string') return;
+
+                    report('eval() called via setInterval("' + fn + '")', phantomas.getCaller(), phantomas.getBacktrace(), 'evalCalls');
+                });
+
+                // spy document.write(ln)
+                phantomas.spy(document, 'write', function(arg) {
+                    report('document.write() used', phantomas.getCaller(), phantomas.getBacktrace(), 'documentWriteCalls');
+                });
+
+                phantomas.spy(document, 'writeln', function(arg) {
+                    report('document.writeln() used', phantomas.getCaller(), phantomas.getBacktrace(), 'documentWriteCalls');
+                });
+            })(window.__phantomas);
+        });
+    });
+};
diff --git a/lib/tools/phantomas/phantomasWrapper.js b/lib/tools/phantomas/phantomasWrapper.js
index 4954096..4515a60 100644
--- a/lib/tools/phantomas/phantomasWrapper.js
+++ b/lib/tools/phantomas/phantomasWrapper.js
@@ -37,6 +37,7 @@ var PhantomasWrapper = function() {
                 'eventListeners', // overridden
                 'filmStrip', // not needed
                 'har', // not needed for the moment
+                'javaScriptBottlenecks', // needs to be launched after custom module scopeYLT
                 'pageSource', // not needed
                 'screenshot', // not needed for the moment
                 'waitForSelector', // not needed