diff --git a/book.json b/book.json
index 839600e50..a5e258ac3 100644
--- a/book.json
+++ b/book.json
@@ -192,6 +192,10 @@
         {
           "lang": "ss",
           "name": "Scheme"
+        },
+        {
+          "lang": "kotlin",
+          "name": "Kotlin"
         }
       ]
     }