diff --git a/config/_default/markup.toml b/config/_default/markup.toml
index 45a2959a..64062d84 100644
--- a/config/_default/markup.toml
+++ b/config/_default/markup.toml
@@ -1,2 +1,6 @@
+[tableOfContents]
+startLevel = 1
+endLevel = 3
+
 [goldmark.renderer]
 unsafe = true