diff --git a/13-inch-thin-cannon/configuration.nix b/13-inch-thin-cannon/configuration.nix
index aca4d59..d09b002 100644
--- a/13-inch-thin-cannon/configuration.nix
+++ b/13-inch-thin-cannon/configuration.nix
@@ -175,8 +175,9 @@
   # services.xserver.libinput.enable = true;
 
   # Define a user account. Don't forget to set a password with ‘passwd’.
+  # nushell is only for file_magic: `users.defaultUserShell` would also change
+  # root's login shell, breaking POSIX-sh remote commands (ssh, sudo, scripts).
   users = {
-    defaultUserShell = pkgs.nushell;
     users.file_magic = {
       shell = pkgs.nushell;
       isNormalUser = true;