diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 3ce90cb..e8baccc 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -11,7 +11,7 @@ jobs:
     strategy:
       matrix:
         nixPath:
-          - nixpkgs=https://github.com/NixOS/nixpkgs/archive/nixos-20.09.tar.gz
+          - nixpkgs=https://github.com/NixOS/nixpkgs/archive/nixos-21.05.tar.gz
           - nixpkgs=https://github.com/NixOS/nixpkgs/archive/nixpkgs-unstable.tar.gz
         os: [ ubuntu-latest, macos-latest ]
     runs-on: ${{ matrix.os }}