diff --git a/.github/workflows/book.yml b/.github/workflows/book.yml
index a78e8a2ef6..eee433b322 100644
--- a/.github/workflows/book.yml
+++ b/.github/workflows/book.yml
@@ -3,7 +3,7 @@ name: mdbook
 on:
   push:
     branches:
-      - master
+      - unstable
 
 jobs:
   build-and-upload-to-s3: