diff --git a/.config/bash/module/Nix.sh b/.config/bash/module/Nix.sh
index cc18318..f0c9f65 100644
--- a/.config/bash/module/Nix.sh
+++ b/.config/bash/module/Nix.sh
@@ -47,14 +47,14 @@ function nix_update() {
 	nixos-rebuild switch -I nixos-config=/root/.config/linux/system/${target}/Configuration.nix
 }
 
-# Upgrade system.
+# Upgrade system. Applies after reboot.
 # Optionally force the hostname.
 # Usage: nix_upgrade [HOSTNAME]
 function nix_upgrade() {
 	local target="${1}"
 	[[ "${target}" = "" ]] && target="${HOSTNAME}"
 
-	nixos-rebuild switch --upgrade-all -I nixos-config=/root/.config/linux/system/${target}/Configuration.nix
+	nixos-rebuild boot --upgrade-all -I nixos-config=/root/.config/linux/system/${target}/Configuration.nix
 }
 
 # Free up root space.