diff --git a/pkgs/development/python-modules/black/default.nix b/pkgs/development/python-modules/black/default.nix
index 7abc18d383e7..fc729dd399d2 100644
--- a/pkgs/development/python-modules/black/default.nix
+++ b/pkgs/development/python-modules/black/default.nix
@@ -1,5 +1,5 @@
 { stdenv, buildPythonPackage, fetchPypi, pythonOlder
-, attrs, click, toml, appdirs, aiohttp
+, attrs, click, toml, appdirs, aiohttp, aiohttp-cors
 , glibcLocales, pytest }:
 
 buildPythonPackage rec {
@@ -23,7 +23,7 @@ buildPythonPackage rec {
       --deselect tests/test_black.py::BlackTestCase::test_failed_formatting_does_not_get_cached
   '';
 
-  propagatedBuildInputs = [ attrs appdirs click toml aiohttp ];
+  propagatedBuildInputs = [ attrs appdirs click toml aiohttp aiohttp-cors ];
 
   meta = with stdenv.lib; {
     description = "The uncompromising Python code formatter";