diff --git a/doc/manual/src/installation/upgrading.md b/doc/manual/src/installation/upgrading.md
index 47618e2f5..38edcdbc5 100644
--- a/doc/manual/src/installation/upgrading.md
+++ b/doc/manual/src/installation/upgrading.md
@@ -16,7 +16,7 @@ nix (Nix) 2.18.1
 > Writing to the [local store](@docroot@/store/types/local-store.md) with a newer version of Nix, for example by building derivations with [`nix-build`](@docroot@/command-ref/nix-build.md) or [`nix-store --realise`](@docroot@/command-ref/nix-store/realise.md), may change the database schema!
 > Reverting to an older version of Nix may therefore require purging the store database before it can be used.
 
-### Linux multi-user
+## Linux multi-user
 
 ```console
 $ sudo su