diff --git a/lib/web/JsonpMainTemplatePlugin.js b/lib/web/JsonpMainTemplatePlugin.js
index ea00236027c..0a534466434 100644
--- a/lib/web/JsonpMainTemplatePlugin.js
+++ b/lib/web/JsonpMainTemplatePlugin.js
@@ -29,6 +29,7 @@ class JsonpMainTemplatePlugin {
 			return false;
 		};
 
+		// TODO webpack 5, no adding to .hooks, use WeakMap and static methods
 		["jsonpScript", "linkPreload", "linkPrefetch"].forEach(hook => {
 			if (!mainTemplate.hooks[hook]) {
 				mainTemplate.hooks[hook] = new SyncWaterfallHook([