diff --git a/tests/mocha/index.html b/tests/mocha/index.html
index 6eb47e3d9..2d51a1b52 100644
--- a/tests/mocha/index.html
+++ b/tests/mocha/index.html
@@ -24,7 +24,6 @@
     <script src="../../node_modules/chai/chai.js"></script>
     <script src="../../node_modules/mocha/mocha.js"></script>
     <script src="../../node_modules/sinon/pkg/sinon.js"></script>
-    <!-- <script src="../../node_modules/@blockly/dev-tools/dist/index.js"></script> -->
     <script>
       mocha.setup({
         ui: 'tdd'