diff --git a/mkdocs.yml b/mkdocs.yml
index 35a32d30a6134cc8b15a939bb46947cea3fc8650..47b86febff586bde1103449fa18d2777a8641fbb 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -183,3 +183,4 @@ pages:
 markdown_extensions:
     - toc:
         permalink: True
+        separator: "_"