diff --git a/default.nix b/default.nix
index 34eaa19df2..2e938403c8 100644
--- a/default.nix
+++ b/default.nix
@@ -40,6 +40,4 @@ ocamlPackages.buildDunePackage rec {
     license = stdenv.lib.licenses.bsd3;
     maintainers = with stdenv.lib.maintainers; [ rybern ];
   };
-
-  inherit pkgs;
 }
diff --git a/shell.nix b/shell.nix
index 21c0448872..bcfe769786 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,6 +1,13 @@
 let derivation = import ./default.nix; in
 
-with derivation.pkgs;
+with (import (builtins.fetchTarball {
+  name = "nixpkgs-19.09";
+  # Tarball of tagged release of Nixpkgs 19.09
+  url = "https://github.com/NixOS/nixpkgs/archive/19.09.tar.gz";
+  # Tarball hash obtained using `nix-prefetch-url --unpack <url>`
+  sha256 = "0mhqhq21y5vrr1f30qd2bvydv4bbbslvyzclhw0kdxmkgg3z4c92";
+}) {});
+
 stdenv.mkDerivation rec {
   name = "stanc-env";