diff --git a/packages/playwright-test/bundles/babel/src/babelBundleImpl.ts b/packages/playwright-test/bundles/babel/src/babelBundleImpl.ts
index 2a9b246248..c71f24eec3 100644
--- a/packages/playwright-test/bundles/babel/src/babelBundleImpl.ts
+++ b/packages/playwright-test/bundles/babel/src/babelBundleImpl.ts
@@ -70,6 +70,7 @@ function babelTransformOptions(isTypeScript: boolean, isModule: boolean, plugins
 
   if (!isModule) {
     plugins.push([require('@babel/plugin-transform-modules-commonjs')]);
+    // This converts async imports to require() calls so that we can intercept them with pirates.
     plugins.push([require('@babel/plugin-proposal-dynamic-import')]);
   } else {
     plugins.push([require('@babel/plugin-syntax-import-assertions')]);