diff --git a/pkgs/development/python-modules/pytest-mockservers/default.nix b/pkgs/development/python-modules/pytest-mockservers/default.nix
index d65b29d7662f..d524457ebbb4 100644
--- a/pkgs/development/python-modules/pytest-mockservers/default.nix
+++ b/pkgs/development/python-modules/pytest-mockservers/default.nix
@@ -2,6 +2,7 @@
 , buildPythonPackage
 , pythonOlder
 , fetchFromGitHub
+, fetchpatch
 , poetry-core
 , aiohttp
 , pytest
@@ -19,13 +20,17 @@ buildPythonPackage rec {
     owner = "Gr1N";
     repo = pname;
     rev = version;
-    sha256 = "0xql0fnw7m2zn103601gqbpyd761kzvgjj2iz9hjsv56nr4z1g9i";
+    hash = "sha256-Mb3wSbambC1h+lFI+fafwZzm78IvADNAsF/Uw60DFHc=";
   };
 
-  postPatch = ''
-    substituteInPlace pyproject.toml \
-      --replace "poetry.masonry.api" "poetry.core.masonry.api"
-  '';
+  patches = [
+    # https://github.com/Gr1N/pytest-mockservers/pull/75
+    (fetchpatch {
+      name = "use-poetry-core.patch";
+      url = "https://github.com/Gr1N/pytest-mockservers/commit/c7731186a4e12851ab1c15ab56e652bb48ed59c4.patch";
+      hash = "sha256-/5X3xjJwt2gs3t6f/6n1QZ+CTBq/5+cQE+MgNWyz+Hs=";
+    })
+  ];
 
   nativeBuildInputs = [
     poetry-core
@@ -40,6 +45,8 @@ buildPythonPackage rec {
     pytest-asyncio
   ];
 
+  __darwinAllowLocalNetworking = true;
+
   nativeCheckInputs = [
     pytestCheckHook
   ];