1 files changed, 1 insertions, 1 deletions
diff --git a/shell.nix b/shell.nix
index 1e231f9..38ee8f5 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,4 +1,4 @@
-{ pkgs ? import <nixpkgs> { }, ... }:
+{ pkgs ? import (fetchTarball https://github.com/NixOS/nixpkgs/archive/20.09.tar.gz) { }, ... }:
 
 pkgs.stdenvNoCC.mkDerivation rec {
   name = "pycl-env";