diff --git a/_infrastructure/tests/runner.js b/_infrastructure/tests/runner.js
index 21e6e2ac13..99e5c22a6a 100644
--- a/_infrastructure/tests/runner.js
+++ b/_infrastructure/tests/runner.js
@@ -537,7 +537,7 @@ var DefinitelyTyped;
             function Tsc() {
             }
             Tsc.run = function (tsfile, callback) {
-                Exec.exec('node ./_infrastructure/tests/typescript/tsc.js ', [tsfile], function (ExecResult) {
+                Exec.exec('node ./_infrastructure/tests/typescript/tsc.js --module commonjs ', [tsfile], function (ExecResult) {
                     callback(ExecResult);
                 });
             };