diff --git a/run-fmt.sh b/run-fmt.sh
index 09bf12f..b4fee1c 100755
--- a/run-fmt.sh
+++ b/run-fmt.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 function format() {
     # format file
@@ -16,7 +16,7 @@ function format() {
         echo "failed format validation: $1"
         exit 1
     fi
-    
+
     local imports=$(rg "#import \"([a-z0-9/\-]+\.typ)\"" -Nor '$1' "$1")
 
     # format all included files
@@ -39,4 +39,4 @@ case $1 in
     echo "unknown option: $1"
     exit 1
     ;;
-esac
\ No newline at end of file
+esac
diff --git a/shell.nix b/shell.nix
index 61ee97a..a71ba0e 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,5 +1,5 @@
 let
-  nixpkgs = fetchTarball "https://github.com/NixOS/nixpkgs/tarball/nixos-24.05";
+  nixpkgs = fetchTarball "https://github.com/NixOS/nixpkgs/tarball/nixos-unstable";
   pkgs = import nixpkgs { config = {}; overlays = []; };
 in