diff --git a/doc/manual/source/installation/index.md b/doc/manual/source/installation/index.md
index 48725c1ba..3c09f1031 100644
--- a/doc/manual/source/installation/index.md
+++ b/doc/manual/source/installation/index.md
@@ -30,6 +30,8 @@ $ curl -L https://nixos.org/nix/install | sh -s -- --daemon
 
 > Single-user is not supported on Mac.
 
+> `warning: installing Nix as root is not supported by this script!`
+
 This installation has less requirements than the multi-user install, however it
 cannot offer equivalent sharing, isolation, or security.