diff --git a/book/features/external_toc.md b/book/features/external_toc.md
index 46fa6cb..c80c8c8 100644
--- a/book/features/external_toc.md
+++ b/book/features/external_toc.md
@@ -6,7 +6,7 @@
 This page is useful for user type 3-5.
 ```
 
-{bdg-link-secondary}`Python Package: teachbooks <./overview#teachBooks-python-package>`
+{bdg-link-secondary}`Python Package: teachbooks <./overview#teachbooks-python-package>`
 
 ## Introduction