diff --git a/pkgs/python-packages/default.nix b/pkgs/python-packages/default.nix
index beb4551..0c0f9d3 100644
--- a/pkgs/python-packages/default.nix
+++ b/pkgs/python-packages/default.nix
@@ -34,9 +34,6 @@ in {
   # autobahn 20.12.3, required by joinmarketclient
   autobahn = callPackage ./specific-versions/autobahn.nix {};
 
-  # klein 20.6.0, required by joinmarketclient
-  klein = callPackage ./specific-versions/klein.nix {};
-
   # tubes 0.2.0, required by klein
   tubes = callPackage ./specific-versions/tubes.nix {};
 
diff --git a/pkgs/python-packages/jmclient/default.nix b/pkgs/python-packages/jmclient/default.nix
index 3a73dd4..6b9d8ef 100644
--- a/pkgs/python-packages/jmclient/default.nix
+++ b/pkgs/python-packages/jmclient/default.nix
@@ -11,6 +11,11 @@ buildPythonPackage rec {
   # configparser may need to be compiled with python_version<"3.2"
   propagatedBuildInputs = [ future configparser joinmarketbase mnemonic argon2_cffi bencoderpyx pyaes klein pyjwt autobahn cryptography ];
 
+  patchPhase = ''
+    substituteInPlace setup.py \
+      --replace "'klein==20.6.0'" "'klein==21.8.0'"
+  '';
+
   meta = with lib; {
     description = "Client library for Bitcoin coinjoins";
     homepage = "https://github.com/Joinmarket-Org/joinmarket-clientserver";
diff --git a/pkgs/python-packages/specific-versions/klein.nix b/pkgs/python-packages/specific-versions/klein.nix
deleted file mode 100644
index 4b5be48..0000000
--- a/pkgs/python-packages/specific-versions/klein.nix
+++ /dev/null
@@ -1,29 +0,0 @@
-{ lib, buildPythonPackage, fetchPypi, python
-, attrs, enum34, hyperlink, incremental, six, twisted, typing, tubes, werkzeug, zope_interface
-, hypothesis, treq
-}:
-
-buildPythonPackage rec {
-  pname = "klein";
-  version = "20.6.0";
-
-  src = fetchPypi {
-    inherit pname version;
-    sha256 = "sha256-ZYS5zf9JWbnc7pWhwcIAEPUhoqEsT/PN2LkDqbDpk/Y=";
-  };
-
-  propagatedBuildInputs = [ attrs enum34 hyperlink incremental six twisted typing tubes werkzeug zope_interface ];
-
-  checkInputs = [ hypothesis treq ];
-
-  checkPhase = ''
-    ${python.interpreter} -m twisted.trial -j $NIX_BUILD_CORES klein
-  '';
-
-  meta = with lib; {
-    description = "Klein Web Micro-Framework";
-    homepage    = "https://github.com/twisted/klein";
-    license     = licenses.mit;
-    maintainers = with maintainers; [ exarkun ];
-  };
-}