diff --git a/pkgs/development/python-modules/dulwich/default.nix b/pkgs/development/python-modules/dulwich/default.nix
index fc9245f33777..97b27d14bd35 100644
--- a/pkgs/development/python-modules/dulwich/default.nix
+++ b/pkgs/development/python-modules/dulwich/default.nix
@@ -74,6 +74,8 @@ buildPythonPackage rec {
   disabledTestPaths = [
     # missing test inputs
     "dulwich/contrib/test_swift_smoke.py"
+    # flaky on high core count >4
+    "dulwich/tests/compat/test_client.py"
   ];
 
   pythonImportsCheck = [