diff --git a/default.nix b/default.nix
index 51d5a62..e3547b1 100644
--- a/default.nix
+++ b/default.nix
@@ -1,143 +1,16 @@
 let
-  pkgs = import <nixpkgs> { };
+  hostPkgs = import <nixpkgs> {};
+  pkgs = hostPkgs.fetchFromGitHub {
+    owner = "NixOS";
+    repo = "nixpkgs";
+    ref = "nixos-22.05";
+    rev = "45c9736ed69800a6ff2164fb4538c9e40dad25d6";
+  };
 in
 
 self: super: rec {
   python39 = super.python39.override {
     packageOverrides = python-self: python-super: {
-      graphql-core = python-super.buildPythonPackage rec {
-        pname = "graphql-core";
-          version = "3.2.0";
-          format = "setuptools";
-          src = python-super.fetchPypi {
-            inherit pname version;
-            sha256 = "sha256-huKgvgCL/eGe94OI3opyWh2UKpGQykMcJKYIN5c4A84=";
-          };
-          checkInputs = [
-            python-super.pytest-asyncio
-            python-super.pytest-benchmark
-            python-super.pytestCheckHook
-          ];
-          pythonImportsCheck = [
-            "graphql"
-          ];
-      };
-      starlette = python-super.buildPythonPackage rec {
-        pname = "starlette";
-          version = "0.19.0";
-          format = "setuptools";
-          src = pkgs.fetchFromGitHub {
-            owner = "encode";
-            repo = pname;
-            rev = version;
-            sha256 = "sha256-gjRTMzoQ8pqxjIusRwRXGs72VYo6xsp2DSUxmEr9KxU=";
-          };
-          postPatch = ''
-            # remove coverage arguments to pytest
-            sed -i '/--cov/d' setup.cfg
-          '';
-
-          propagatedBuildInputs = with self.python39Packages; [
-            aiofiles
-            anyio
-            itsdangerous
-            jinja2
-            python-multipart
-            pyyaml
-            requests
-          ];
-
-          checkInputs = with self.python39Packages; [
-            aiosqlite
-            databases
-            pytestCheckHook
-            trio
-            typing-extensions
-          ];
-
-          disabledTests = [
-            # asserts fail due to inclusion of br in Accept-Encoding
-            "test_websocket_headers"
-            "test_request_headers"
-          ];
-
-          pythonImportsCheck = [
-            "starlette"
-          ];
-      };
-      fastapi = python-super.buildPythonPackage rec {
-        pname = "fastapi";
-          version = "0.75.2";
-          format = "flit";
-          src = pkgs.fetchFromGitHub {
-            owner = "tiangolo";
-            repo = pname;
-            rev = version;
-            hash = "sha256-B4q3Q256Sj4jTQt1TDm3fiEaQKdVxddCF9+KsxkkTWo=";
-          };
-          propagatedBuildInputs = with self.python39Packages;  [
-            starlette
-            pydantic
-          ];
-
-          checkInputs = with self.python39Packages; [
-            aiosqlite
-            databases
-            flask
-            httpx
-            passlib
-            peewee
-            python-jose
-            pytestCheckHook
-            pytest-asyncio
-            sqlalchemy
-            trio
-            bcrypt
-          ];
-
-          patches = [
-            # Bump starlette, https://github.com/tiangolo/fastapi/pull/4483
-            (pkgs.fetchpatch {
-              name = "support-later-starlette.patch";
-              # PR contains multiple commits
-              url = "https://patch-diff.githubusercontent.com/raw/tiangolo/fastapi/pull/4483.patch";
-              sha256 = "sha256-ZWaqAd/QYEYRL1hSQdXdFPgWgdmOill2GtmEn33vz2U=";
-            })
-          ];
-
-          postPatch = ''
-            substituteInPlace pyproject.toml \
-              --replace "starlette ==" "starlette >="
-          '';
-
-          pytestFlagsArray = [
-            # ignoring deprecation warnings to avoid test failure from
-            # tests/test_tutorial/test_testing/test_tutorial001.py
-            "-W ignore::DeprecationWarning"
-          ];
-
-          disabledTestPaths = [
-            # Disabled tests require orjson which requires rust nightly
-            "tests/test_default_response_class.py"
-            # Don't test docs and examples
-            "docs_src"
-          ];
-
-          disabledTests = [
-            "test_get_custom_response"
-            # Failed: DID NOT RAISE <class 'starlette.websockets.WebSocketDisconnect'>
-            "test_websocket_invalid_data"
-            "test_websocket_no_credentials"
-            # TypeError: __init__() missing 1...starlette-releated
-            "test_head"
-            "test_options"
-            "test_trace"
-          ];
-
-          pythonImportsCheck = [
-            "fastapi"
-          ];
-      };
       strawberry_graphql = python-super.buildPythonPackage rec {
         pname = "strawberry-graphql";
         version = "0.123.0";