diff --git a/rollup.config.js b/rollup.config.js
index 316f81be..5b31cd1a 100644
--- a/rollup.config.js
+++ b/rollup.config.js
@@ -52,6 +52,7 @@ export default {
       },
     }),
     babel({
+      // https://www.npmjs.com/package/@rollup/plugin-babel#babelhelpers
       babelHelpers: 'runtime',
     }),
   ],