diff --git a/lib/reporters/machineout.js b/lib/reporters/machineout.js
index 8e611fe47..d9a7c4d5d 100644
--- a/lib/reporters/machineout.js
+++ b/lib/reporters/machineout.js
@@ -58,7 +58,10 @@ exports.run = function (files, options, callback) {
         if (delimiter === undefined) {
             delimiter = ':';
         }
-        traceback = stack.split('\n');
+        traceback = stack.split(/\n/).filter(function (line) {
+            // exclude line of "types.js"
+            return ! RegExp(/nodeunit\/lib\/types.js:/).test(line);
+        });
         firstline = traceback.shift();
         trace = parseTrace(traceback[0]);
         return {filename: trace.filename, row: trace.row, column: trace.column, message: firstline};