diff --git a/pkgs/development/python-modules/frozendict/default.nix b/pkgs/development/python-modules/frozendict/default.nix
index 95c946a7751f..d7e12cc061d5 100644
--- a/pkgs/development/python-modules/frozendict/default.nix
+++ b/pkgs/development/python-modules/frozendict/default.nix
@@ -8,14 +8,14 @@
 
 buildPythonPackage rec {
   pname = "frozendict";
-  version = "2.2.0";
+  version = "2.3.0";
   format = "setuptools";
 
   disabled = !isPy3k;
 
   src = fetchPypi {
     inherit pname version;
-    sha256 = "sha256-jj1HNfmhPRB3Vn5WhHFmPzJE+FrImyP4yzHPIx2+Rbk=";
+    sha256 = "1dd0bqhai4k3fj9ydcwmc9hvbmrsklk349ys21w8x4n5xynk2hns";
   };
 
   pythonImportsCheck = [
diff --git a/pkgs/servers/matrix-synapse/default.nix b/pkgs/servers/matrix-synapse/default.nix
index b94257e6d5e2..84e64af86658 100644
--- a/pkgs/servers/matrix-synapse/default.nix
+++ b/pkgs/servers/matrix-synapse/default.nix
@@ -18,6 +18,12 @@ buildPythonApplication rec {
     sha256 = "sha256-qhwFRveFCwflQmVCwzThC8sP+YCqckgCaXAc3IRms0g=";
   };
 
+  # frozendict version constraint is to avoid a debian issue we don't have
+  postPatch = ''
+    substituteInPlace synapse/python_dependencies.py \
+      --replace '"frozendict' '"frozendict", #'
+  '';
+
   buildInputs = [ openssl ];
 
   propagatedBuildInputs = [