diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d4ce8ca..7dc755a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -11,7 +11,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-latest, macos-latest, windows-latest]
+        os: [ubuntu-latest, windows-latest]
     steps:
       - uses: actions/checkout@v2
       - uses: actions-rs/install@v0.1
diff --git a/shell.nix b/shell.nix
index 6795544..0536653 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,9 +1,6 @@
 let
-  nushell = self: super: { nushell = super.nushell.overrideAttrs (old: { checkPhase = ""; }); };
   pkgs = import (fetchTarball "https://github.com/NixOS/nixpkgs/archive/20.09.tar.gz") {};
-  pkgs-master = import (fetchTarball "https://github.com/NixOS/nixpkgs/archive/470e4a9bbc98b171a7e733dfc9e62531f7b9ceca.tar.gz") {
-    overlays = [ nushell ];
-  };
+  pkgs-master = import (fetchTarball "https://github.com/NixOS/nixpkgs/archive/470e4a9bbc98b171a7e733dfc9e62531f7b9ceca.tar.gz") {};
   pkgs-python = pkgs.python3.withPackages (pkgs: [ pkgs.black pkgs.mypy pkgs.pylint ]);
 in
 pkgs.mkShell {