diff --git a/pkgs/development/python-modules/mcp/default.nix b/pkgs/development/python-modules/mcp/default.nix
index 1a0519f1e2ed..9df48a47c598 100644
--- a/pkgs/development/python-modules/mcp/default.nix
+++ b/pkgs/development/python-modules/mcp/default.nix
@@ -52,15 +52,10 @@ buildPythonPackage rec {
     hash = "sha256-fSQCvKaNMeCzguM2tcTJJlAeZQmzSJmbfEK35D8pQcs=";
   };
 
+  # time.sleep(0.1) feels a bit optimistic and it has been flaky whilst
+  # testing this on macOS under load.
   postPatch = lib.optionalString stdenv.buildPlatform.isDarwin ''
-    # time.sleep(0.1) feels a bit optimistic and it has been flaky whilst
-    # testing this on macOS under load.
-    substituteInPlace \
-      "tests/client/test_stdio.py" \
-      "tests/server/fastmcp/test_integration.py" \
-      "tests/shared/test_ws.py" \
-      "tests/shared/test_sse.py" \
-      "tests/shared/test_streamable_http.py" \
+    substituteInPlace tests/client/test_stdio.py \
       --replace-fail "time.sleep(0.1)" "time.sleep(1)"
   '';