diff --git a/.config/bash/module/Nix.sh b/.config/bash/module/Nix.sh
index d84f51b..cf90f13 100644
--- a/.config/bash/module/Nix.sh
+++ b/.config/bash/module/Nix.sh
@@ -82,7 +82,7 @@ function nix_shell() {
 	local name="${1,,}"
 	[[ "${name}" = "" ]] && name="main"
 
-	nix_shell="${name}" nix-shell ~/.config/linux/shell/"${name^}".nix
+	NIX_SHELL="${name}" nix-shell ~/.config/linux/shell/"${name^}".nix
 }
 alias shell="nix_shell"
 
@@ -102,7 +102,7 @@ function nix_tmpshell() {
 		pkgs+=("nixpkgs#${pkg}")
 	done
 
-	nix_shell="${1}" nix shell ${pkgs[@]}
+	NIX_SHELL="${1}" nix shell ${pkgs[@]}
 }
 alias tmpshell="nix_tmpshell"
 
diff --git a/.config/bash/module/Ps1.sh b/.config/bash/module/Ps1.sh
index cd0a303..e9ce6cb 100644
--- a/.config/bash/module/Ps1.sh
+++ b/.config/bash/module/Ps1.sh
@@ -73,8 +73,8 @@ function __prompt_command() {
 	PS1+="\[${color_default}\]"
 
 	# Show nix shell name.
-	if [ -n "${nix_shell}" ]; then
-		PS1+="${color_white}${nix_shell}${color_default} "
+	if [ -n "${NIX_SHELL}" ]; then
+		PS1+="${color_white}${NIX_SHELL}${color_default} "
 	fi
 
 	# Show remote connections.