diff --git a/default.nix b/default.nix
index 57b712d..aa7cfd7 100644
--- a/default.nix
+++ b/default.nix
@@ -33,6 +33,22 @@ rec {
   rust-synapse-compress-state = pkgs.callPackage ./pkgs/rust-synapse-compress-state { };
   matrix-corporal = pkgs.callPackage ./pkgs/matrix-corporal { };
 
+  matrix-synapse = pkgs.matrix-synapse.overrideAttrs (oldAttrs: rec {
+    propagatedBuildInputs = oldAttrs.propagatedBuildInputs
+    ++ [ ( pkgs.python3.pkgs.buildPythonPackage {
+      pname = "txredisapi";
+      version = "1.4.7";
+
+      src = pkgs.python3.pkgs.fetchPypi {
+        pname = "txredisapi";
+        version = "1.4.7";
+        sha256 = "1fqjr2z3wqgapa2fbxkr4vcf33ql1v9cgy58vjmhimim3vsl7k76";
+      };
+      propagatedBuildInputs = [ pkgs.python3.pkgs.twisted ];
+    })
+    pkgs.python3.pkgs.hiredis ];
+  });
+
   rank_photos = pkgs.callPackage ./pkgs/rank_photos { };
 
   # grav1 = pkgs.callPackage ./pkgs/grav1/server.nix { wsgiserver = wsgiserver; setuptools = pkgs.python3Packages.setuptools; };