diff --git a/cnames_active.js b/cnames_active.js
index 8a84672c..13b8745b 100644
--- a/cnames_active.js
+++ b/cnames_active.js
@@ -913,6 +913,7 @@ var cnames_active = {
   "geniucker": "geniucker.github.io",
   "genpasswd": "exos.github.io/genpasswd", // noCF? (don´t add this in a new PR)
   "gem": "gem-docs.netlify.app",
+  "gem-book": "gem-book.netlify.app",
   "geolocation-promise": "js-pugilist.github.io/geolocation-promise",
   "george": "georgeyue.github.io/george",
   "geralcr": "geralcr.github.io/Portafolio",