diff --git a/pkgs/by-name/ma/matrix-synapse-unwrapped/package.nix b/pkgs/by-name/ma/matrix-synapse-unwrapped/package.nix
index cd1105642da4..d306a0c87be9 100644
--- a/pkgs/by-name/ma/matrix-synapse-unwrapped/package.nix
+++ b/pkgs/by-name/ma/matrix-synapse-unwrapped/package.nix
@@ -2,6 +2,7 @@
   lib,
   stdenv,
   fetchFromGitHub,
+  fetchpatch,
   python3,
   openssl,
   libiconv,
@@ -33,6 +34,15 @@ python3.pkgs.buildPythonApplication rec {
     hash = "sha256-PdAyEGLYmMLgcPQjzjuwvQo55olKgr079gsgQnUoKTM=";
   };
 
+  patches = [
+    # fix compatibility with authlib 1.5.2
+    # https://github.com/element-hq/synapse/pull/18390
+    (fetchpatch {
+      url = "https://github.com/element-hq/synapse/commit/c9adbc6a1ce6039b1c04ae3298e463a3e3b25c38.patch";
+      hash = "sha256-0EZL0esZ6IEjmBV1whSpfZoFsMJ2yZQPi1GjW7NQ484=";
+    })
+  ];
+
   postPatch = ''
     # Remove setuptools_rust from runtime dependencies
     # https://github.com/element-hq/synapse/blob/v1.69.0/pyproject.toml#L177-L185