diff --git a/nixng/containers/matrix/synapse/0001-Fix-http-s-proxy-authentication.patch b/nixng/containers/matrix/synapse/0001-Fix-http-s-proxy-authentication.patch
new file mode 100644
index 0000000..ea62fa4
--- /dev/null
+++ b/nixng/containers/matrix/synapse/0001-Fix-http-s-proxy-authentication.patch
@@ -0,0 +1,36 @@
+From 3f0f28bca95f95e227ed9b7aff27e48a445564fd Mon Sep 17 00:00:00 2001
+From: magic_rb <richard@brezak.sk>
+Date: Mon, 16 Oct 2023 17:29:45 +0200
+Subject: [PATCH] Fix http/s proxy authentication
+
+Signed-off-by: magic_rb <richard@brezak.sk>
+---
+ changelog.d/16504.bugfix           | 1 +
+ synapse/http/connectproxyclient.py | 3 +--
+ 2 files changed, 2 insertions(+), 2 deletions(-)
+ create mode 100644 changelog.d/16504.bugfix
+
+diff --git a/changelog.d/16504.bugfix b/changelog.d/16504.bugfix
+new file mode 100644
+index 000000000..60839c474
+--- /dev/null
++++ b/changelog.d/16504.bugfix
+@@ -0,0 +1 @@
++Fix a bug introduced in Synapse 1.41 where HTTP(S) forward proxy authorization would fail when using basic HTTP authentication with a long `username:password` string.
+diff --git a/synapse/http/connectproxyclient.py b/synapse/http/connectproxyclient.py
+index 636efc33e..5bedca922 100644
+--- a/synapse/http/connectproxyclient.py
++++ b/synapse/http/connectproxyclient.py
+@@ -59,8 +59,7 @@ class BasicProxyCredentials(ProxyCredentials):
+             a Proxy-Authorization header.
+         """
+         # Encode as base64 and prepend the authorization type
+-        return b"Basic " + base64.encodebytes(self.username_password)
+-
++        return b"Basic " + base64.b64encode(self.username_password)
+ 
+ @attr.s(auto_attribs=True)
+ class BearerProxyCredentials(ProxyCredentials):
+-- 
+2.42.0
+
diff --git a/nixng/containers/matrix/synapse/synapse-package.nix b/nixng/containers/matrix/synapse/synapse-package.nix
index afd74a8..e83fe2a 100644
--- a/nixng/containers/matrix/synapse/synapse-package.nix
+++ b/nixng/containers/matrix/synapse/synapse-package.nix
@@ -10,12 +10,7 @@ pkgs:
   matrix-synapse-unwrapped =
     pkgs.matrix-synapse-unwrapped.overridePythonAttrs (old: {
       patches = (old.patches or []) ++ [
-        ((pkgs.fetchurl {
-          url = "https://patch-diff.githubusercontent.com/raw/matrix-org/synapse/pull/16504.patch";
-          hash = "sha256-hjUOmsl06gVPewRdg/DyO9E5bSkIRNBAFJIrWqUsT6Y=";
-        }) // {
-          requiredSystemFeatures = [ "local" ];
-        })
+        ./0001-Fix-http-s-proxy-authentication.patch
       ];
     });
 })