diff --git a/pkgs/development/python-modules/black/default.nix b/pkgs/development/python-modules/black/default.nix
index 772ad57e7fe3..948d734d5317 100644
--- a/pkgs/development/python-modules/black/default.nix
+++ b/pkgs/development/python-modules/black/default.nix
@@ -20,13 +20,13 @@
 
 buildPythonPackage rec {
   pname = "black";
-  version = "21.8b0";
+  version = "21.9b0";
 
   disabled = pythonOlder "3.6";
 
   src = fetchPypi {
     inherit pname version;
-    sha256 = "sha256-VwYI0oqjrxeSuYxKM326xjZ4d7R7EriKtCCVz8GmJ8I=";
+    sha256 = "sha256-feTPx+trcQ3jJXEtQBJWiRAdIdJSg+7X6ZmHIs8Q65E=";
   };
 
   nativeBuildInputs = [ setuptools-scm ];