diff --git a/src/injected/injected.ts b/src/injected/injected.ts
index 2b94c2d15e1b0..98a6b87476c7f 100644
--- a/src/injected/injected.ts
+++ b/src/injected/injected.ts
@@ -32,6 +32,9 @@ const PuppeteerUtil = Object.freeze({
   createDeferredPromise,
 });
 
+/**
+ * @internal
+ */
 type PuppeteerUtil = typeof PuppeteerUtil;
 
 /**