diff --git a/pkgs/development/python-modules/mcp/default.nix b/pkgs/development/python-modules/mcp/default.nix
index e0f9c268ac28..e68a6ef12382 100644
--- a/pkgs/development/python-modules/mcp/default.nix
+++ b/pkgs/development/python-modules/mcp/default.nix
@@ -1,44 +1,54 @@
 {
-  anyio,
+  lib,
   buildPythonPackage,
-  coreutils,
   fetchFromGitHub,
+
+  # build-system
   hatchling,
+
+  # dependencies
+  anyio,
   httpx,
   httpx-sse,
-  lib,
   pydantic,
   pydantic-settings,
+  python-multipart,
+  sse-starlette,
+  starlette,
+  uvicorn,
+
+  # optional-dependencies
+  # cli
+  python-dotenv,
+  typer,
+  # rich
+  rich,
+  # ws
+  websockets,
+
+  # tests
   pytest-asyncio,
   pytest-examples,
   pytestCheckHook,
-  python-dotenv,
-  rich,
-  sse-starlette,
-  starlette,
-  typer,
-  uvicorn,
-  websockets,
+  requests,
 }:
 
 buildPythonPackage rec {
   pname = "mcp";
-  version = "1.6.0";
+  version = "1.9.0";
   pyproject = true;
 
   src = fetchFromGitHub {
     owner = "modelcontextprotocol";
     repo = "python-sdk";
     tag = "v${version}";
-    hash = "sha256-APm3x4tcDbp8D2ygW43wFyP0llJ6fXZiINHRYShp9ZY=";
+    hash = "sha256-UH91o2ElS0XLjH67R9QaJ/7AeX6oVkqqOc3588D4s0g=";
   };
 
   postPatch = ''
     substituteInPlace pyproject.toml \
       --replace-fail ', "uv-dynamic-versioning"' "" \
       --replace-fail 'dynamic = ["version"]' 'version = "${version}"'
-    substituteInPlace tests/client/test_stdio.py \
-      --replace '/usr/bin/tee' '${lib.getExe' coreutils "tee"}'
   '';
 
   build-system = [ hatchling ];
@@ -53,6 +63,7 @@ buildPythonPackage rec {
     httpx-sse
     pydantic
     pydantic-settings
+    python-multipart
     sse-starlette
     starlette
     uvicorn
@@ -77,6 +88,7 @@ buildPythonPackage rec {
     pytest-asyncio
     pytest-examples
     pytestCheckHook
+    requests
   ] ++ lib.flatten (lib.attrValues optional-dependencies);
 
   pytestFlagsArray = [
@@ -89,6 +101,9 @@ buildPythonPackage rec {
     "test_command_execution"
     # performance-dependent test
     "test_messages_are_executed_concurrently"
+
+    # ExceptionGroup: unhandled errors in a TaskGroup (1 sub-exception)
+    "test_client_session_version_negotiation_failure"
   ];
 
   __darwinAllowLocalNetworking = true;