diff --git a/pkgs/development/python-modules/granian/default.nix b/pkgs/development/python-modules/granian/default.nix
index 2d0a95898814..34144ff5a139 100644
--- a/pkgs/development/python-modules/granian/default.nix
+++ b/pkgs/development/python-modules/granian/default.nix
@@ -1,5 +1,6 @@
 {
   lib,
+  fetchurl,
   fetchFromGitHub,
   rustPlatform,
   cacert,
@@ -34,6 +35,11 @@ buildPythonPackage rec {
   # and allow the final application to make the allocator decision
   # via LD_PRELOAD or similar.
   patches = [
+    (fetchurl {
+      # Refresh expired TLS certificates for tests
+      url = "https://github.com/emmett-framework/granian/commit/189f1bed2effb4a8a9cba07b2c5004e599a6a890.patch";
+      hash = "sha256-7FgVR7/lAh2P5ptGx6jlFzWuk24RY7wieN+aLaAEY+c=";
+    })
     ./no-alloc.patch
   ];