diff --git a/free-programming-books.md b/free-programming-books.md
index 086e78ea47d6254c362cb833e61498102734fd47..1cbc6ecc9684cf770420b31f84080f3f53bc501b 100644
--- a/free-programming-books.md
+++ b/free-programming-books.md
@@ -747,7 +747,7 @@ Kerridge (PDF) (email address *requested*, not required)
 #### Web Performance
 
 * [Book of Speed](http://www.bookofspeed.com) - Stoyan Stefanov
-* [High Performance Browser Networking](http://chimera.labs.oreilly.com/books/1230000000545/index.html) - Ilya Grigorik
+* [High Performance Browser Networking](https://hpbn.co) - Ilya Grigorik
 * [Mature Optimization](http://carlos.bueno.org/optimization/mature-optimization.pdf) - Carlos Bueno (PDF)