diff --git a/shell.nix b/shell.nix
index 3faf34b..93eb166 100644
--- a/shell.nix
+++ b/shell.nix
@@ -11,23 +11,23 @@ let
     };
   };
 
-  update-sources = pkgs.writeShellScriptBin "update-sources" ''
-    set -e
-    git diff --exit-code -s nix/sources.json || (echo "File nix/sources.json has unstaged changes, refusing to update." >&2 && exit 1)
-    git diff --cached --exit-code -s nix/sources.json || (echo "File nix/sources.json has staged changes, refusing to update." >&2 && exit 1)
-    niv update
-    git diff --exit-code -s nix/sources.json && echo "Already up to date." && exit 0
-    git commit -m "Update sources" nix/sources.json
-  '';
+  scripts = {
+    update-sources = ''
+      set -e
+      git diff --exit-code -s nix/sources.json || (echo "File nix/sources.json has unstaged changes, refusing to update." >&2 && exit 1)
+      git diff --cached --exit-code -s nix/sources.json || (echo "File nix/sources.json has staged changes, refusing to update." >&2 && exit 1)
+      niv update
+      git diff --exit-code -s nix/sources.json && echo "Already up to date." && exit 0
+      git commit -m "Update sources" nix/sources.json
+    '';
+  };
 in
 pkgs.mkShell {
   buildInputs = (with pkgs; [
     git
     niv
     nixpkgs-fmt
-  ]) ++ [
-    update-sources
-  ];
+  ]) ++ (builtins.attrValues (builtins.mapAttrs pkgs.writeShellScriptBin scripts));
   shellHook = ''
     ${pre-commit-check.shellHook}
   '';