diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index 16e7f5195025..fa1efffa1f35 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -11600,6 +11600,16 @@ self: super: with self; {
 
   pytest-asyncio = callPackage ../development/python-modules/pytest-asyncio { };
 
+  pytest-asyncio_0_21 = pytest-asyncio.overridePythonAttrs (old: rec {
+    version = "0.21.1";
+    src = pkgs.fetchFromGitHub {
+      owner = "pytest-dev";
+      repo = "pytest-asyncio";
+      rev = "refs/tags/v${version}";
+      hash = "sha256-Wpo8MpCPGiXrckT2x5/yBYtGlzso/L2urG7yGc7SPkA=";
+    };
+  });
+
   pytest-bdd = callPackage ../development/python-modules/pytest-bdd { };
 
   pytest-benchmark = callPackage ../development/python-modules/pytest-benchmark { };