diff --git a/build/build.js b/build/build.js
index 7761f0eb7..90f3fe816 100755
--- a/build/build.js
+++ b/build/build.js
@@ -2,6 +2,7 @@
 
 'use strict'
 
+// Needed so we can require src/module-cache.coffee during generateModuleCache
 require('coffee-script/register')
 
 const cleanOutputDirectory = require('./lib/clean-output-directory')