diff --git a/tests/mocha/index.html b/tests/mocha/index.html
index ba0ce0789..7841f2af1 100644
--- a/tests/mocha/index.html
+++ b/tests/mocha/index.html
@@ -22,6 +22,7 @@
 
     <script src="test_helpers.js"></script>
     <script src="../../blocks/procedures.js"></script>
+    <script src="../../msg/messages.js"></script>
 
     <script src="block_test.js"></script>
     <script src="procedures_test.js"></script>