diff --git a/pkg/hs/default.nix b/pkg/hs/default.nix
index 9b413e1828..f201767f43 100644
--- a/pkg/hs/default.nix
+++ b/pkg/hs/default.nix
@@ -13,7 +13,7 @@ let
     if builtins.pathExists ../.in-static-haskell-nix
       then toString ../. # for the case that we're in static-haskell-nix itself, so that CI always builds the latest version.
       # Update this hash to use a different `static-haskell-nix` version:
-      else fetchTarball https://github.com/nh2/static-haskell-nix/archive/b402b38c3af2300e71caeebe51b5e4e1ae2e924c.tar.gz;
+      else fetchTarball https://github.com/nh2/static-haskell-nix/archive/d1b20f35ec7d3761e59bd323bbe0cca23b3dfc82.tar.gz;
 
   # Pin nixpkgs version
   # By default to the one `static-haskell-nix` provides, but you may also give
@@ -34,8 +34,7 @@ let
   };
 
   # Full invocation, including pinning `nix` version itself.
-  fullBuildScript = pkgs.writeScript "stack2nix-and-build-script.sh" ''
-    #!/usr/bin/env bash
+  fullBuildScript = pkgs.writeShellScript "stack2nix-and-build-script.sh" ''
     set -eu -o pipefail
     STACK2NIX_OUTPUT_PATH=$(${stack2nix-script})
     export NIX_PATH=nixpkgs=${pkgs.path}