diff --git a/pkgs/development/python-modules/black/default.nix b/pkgs/development/python-modules/black/default.nix
index 00678ca420d..315e891030e 100644
--- a/pkgs/development/python-modules/black/default.nix
+++ b/pkgs/development/python-modules/black/default.nix
@@ -22,8 +22,10 @@ buildPythonPackage rec {
   __darwinAllowLocalNetworking = true;
 
   # Don't know why these tests fails
+  # Disable test_expression_diff, because it fails on darwin
   checkPhase = ''
     LC_ALL="en_US.UTF-8" pytest \
+      --deselect tests/test_black.py::BlackTestCase::test_expression_diff \
       --deselect tests/test_black.py::BlackTestCase::test_cache_multiple_files \
       --deselect tests/test_black.py::BlackTestCase::test_failed_formatting_does_not_get_cached
   '';