diff --git a/pkgs/development/python-modules/boltons/default.nix b/pkgs/development/python-modules/boltons/default.nix
index 2caf3b4c6f84..c186017c9c13 100644
--- a/pkgs/development/python-modules/boltons/default.nix
+++ b/pkgs/development/python-modules/boltons/default.nix
@@ -2,6 +2,7 @@
   lib,
   buildPythonPackage,
   fetchFromGitHub,
+  fetchpatch,
   flit-core,
   pytestCheckHook,
 }:
@@ -18,6 +19,14 @@ buildPythonPackage rec {
     hash = "sha256-kBOU17/jRRAGb4MGawY0PY31OJf5arVz+J7xGBoMBkg=";
   };
 
+  patches = [
+    (fetchpatch {
+      name = "pytest9-compat.patch";
+      url = "https://github.com/mahmoud/boltons/commit/a2af58548936c51a3d859f780e54ba170a6829bb.patch";
+      hash = "sha256-NRjfEKb0doJEtS5GyrF0dJYYr2u+ukogfUmmVnsHAwM=";
+    })
+  ];
+
   build-system = [ flit-core ];
 
   nativeCheckInputs = [ pytestCheckHook ];