diff --git a/artiq-fast/shell-dev.nix b/artiq-fast/shell-dev.nix
index aff6905..4e705b8 100644
--- a/artiq-fast/shell-dev.nix
+++ b/artiq-fast/shell-dev.nix
@@ -1,21 +1,20 @@
-{ pkgs ? import <nixpkgs> {}}:
+{ pkgs ? import <nixpkgs> {}
+, artiqpkgs ? import ./default.nix { inherit pkgs; }
+, vivado ? import ./vivado.nix { inherit pkgs; }
+}:
 
-let
-  artiqpkgs = import ./default.nix { inherit pkgs; };
-  vivado = import ./vivado.nix { inherit pkgs; };
-in
-  assert pkgs.lib.asserts.assertMsg (!pkgs.lib.strings.versionAtLeast artiqpkgs.artiq.version "7.0") "For ARTIQ 7+, use 'nix develop' on the flake instead.";
-  pkgs.mkShell {
-    buildInputs = [
-      vivado
-      pkgs.gnumake
-      (pkgs.python3.withPackages(ps: (with ps; [ jinja2 jsonschema numpy paramiko ]) ++ (with artiqpkgs; [ migen microscope misoc jesd204b migen-axi artiq ])))
-      artiqpkgs.cargo-legacy
-      artiqpkgs.rustc-legacy
-      artiqpkgs.binutils-or1k
-      artiqpkgs.binutils-arm
-      artiqpkgs.llvm-or1k
-      artiqpkgs.openocd
-    ];
-    TARGET_AR="or1k-linux-ar";
-  }
+assert pkgs.lib.asserts.assertMsg (!pkgs.lib.strings.versionAtLeast artiqpkgs.artiq.version "7.0") "For ARTIQ 7+, use 'nix develop' on the flake instead.";
+pkgs.mkShell {
+  buildInputs = [
+    vivado
+    pkgs.gnumake
+    (pkgs.python3.withPackages(ps: (with ps; [ jinja2 jsonschema numpy paramiko ]) ++ (with artiqpkgs; [ migen microscope misoc jesd204b migen-axi artiq ])))
+    artiqpkgs.cargo-legacy
+    artiqpkgs.rustc-legacy
+    artiqpkgs.binutils-or1k
+    artiqpkgs.binutils-arm
+    artiqpkgs.llvm-or1k
+    artiqpkgs.openocd
+  ];
+  TARGET_AR="or1k-linux-ar";
+}
diff --git a/artiq-fast/shell.nix b/artiq-fast/shell.nix
index 0f14cc3..b456bac 100644
--- a/artiq-fast/shell.nix
+++ b/artiq-fast/shell.nix
@@ -1,8 +1,7 @@
-{ pkgs ? import <nixpkgs> {}}:
+{ pkgs ? import <nixpkgs> {}
+, artiqpkgs ? import ./default.nix { inherit pkgs; }
+}:
 
-let 
-  artiqpkgs = import ./default.nix { inherit pkgs; };
-in
-  pkgs.mkShell {
-    buildInputs = [ (pkgs.python3.withPackages(ps: [artiqpkgs.artiq])) ];
-  }
+pkgs.mkShell {
+  buildInputs = [ (pkgs.python3.withPackages(ps: [artiqpkgs.artiq])) ];
+}