diff --git a/flake.lock b/flake.lock
index fe469b2..013a8b5 100644
--- a/flake.lock
+++ b/flake.lock
@@ -2,11 +2,11 @@
   "nodes": {
     "flake-utils": {
       "locked": {
-        "lastModified": 1623875721,
-        "narHash": "sha256-A8BU7bjS5GirpAUv4QA+QnJ4CceLHkcXdRp4xITDB0s=",
+        "lastModified": 1631561581,
+        "narHash": "sha256-3VQMV5zvxaVLvqqUrNz3iJelLw30mIVSfZmAaauM3dA=",
         "owner": "numtide",
         "repo": "flake-utils",
-        "rev": "f7e004a55b120c02ecb6219596820fcd32ca8772",
+        "rev": "7e5bf3925f6fbdfaf50a2a7ca0be2879c4261d19",
         "type": "github"
       },
       "original": {
@@ -17,11 +17,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1628865210,
-        "narHash": "sha256-dB3IA8AYUQDXH+Xy/6nbv4QpIbVl88DphbcxJSUYiX4=",
+        "lastModified": 1631545603,
+        "narHash": "sha256-aT2UoEOnlEBpMRZKBLu/OBsDNTZQS48scjcL936VSLI=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "a445f5829889959d65ad65e5c961d5c67e1cd677",
+        "rev": "b3083bc6933eb7fa4ee7bd4802e9f72b56f3e654",
         "type": "github"
       },
       "original": {
@@ -33,11 +33,11 @@
     },
     "nixpkgsUnstable": {
       "locked": {
-        "lastModified": 1628934079,
-        "narHash": "sha256-CEYsKXNYprs/TvmB7ppkYMALXnfhEw6lg5VaEXgpoec=",
+        "lastModified": 1631614142,
+        "narHash": "sha256-4B/qkXHPWe/1NL4enq6Qp8eNvTGtvoes1ZpnGbmlRwM=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "fd9984fd9a950686e7271ecf01893987a42cdf14",
+        "rev": "071317d543205ee5f5611d391a37582f9b282240",
         "type": "github"
       },
       "original": {
diff --git a/pkgs/python-packages/default.nix b/pkgs/python-packages/default.nix
index 66e0961..bb5cfdd 100644
--- a/pkgs/python-packages/default.nix
+++ b/pkgs/python-packages/default.nix
@@ -17,6 +17,9 @@ in {
   cryptography = callPackage ./cryptography {};
   cryptography_vectors = callPackage ./cryptography/vectors.nix {};
 
+  # twisted 20.3.0, required by joinmarketbase
+  twisted = callPackage ./twisted {};
+
   joinmarketbase = joinmarketPkg ./jmbase;
   joinmarketclient = joinmarketPkg ./jmclient;
   joinmarketbitcoin = joinmarketPkg ./jmbitcoin;
diff --git a/pkgs/python-packages/twisted/default.nix b/pkgs/python-packages/twisted/default.nix
new file mode 100644
index 0000000..4215657
--- /dev/null
+++ b/pkgs/python-packages/twisted/default.nix
@@ -0,0 +1,62 @@
+{ lib, stdenv
+, buildPythonPackage
+, fetchPypi
+, python
+, zope_interface
+, incremental
+, automat
+, constantly
+, hyperlink
+, pyhamcrest
+, attrs
+, pyopenssl
+, service-identity
+, setuptools
+, idna
+}:
+buildPythonPackage rec {
+  pname = "Twisted";
+  version = "20.3.0";
+
+  src = fetchPypi {
+    inherit pname version;
+    extension = "tar.bz2";
+    sha256 = "040yzha6cyshnn6ljgk2birgh6mh2cnra48xp5ina5vfsnsmab6p";
+  };
+
+  propagatedBuildInputs = [ zope_interface incremental automat constantly hyperlink pyhamcrest attrs setuptools ];
+
+  passthru.extras.tls = [ pyopenssl service-identity idna ];
+
+  # Patch t.p._inotify to point to libc. Without this,
+  # twisted.python.runtime.platform.supportsINotify() == False
+  patchPhase = lib.optionalString stdenv.isLinux ''
+    substituteInPlace src/twisted/python/_inotify.py --replace \
+      "ctypes.util.find_library('c')" "'${stdenv.glibc.out}/lib/libc.so.6'"
+  '';
+
+  # Generate Twisted's plug-in cache.  Twisted users must do it as well.  See
+  # http://twistedmatrix.com/documents/current/core/howto/plugin.html#auto3
+  # and http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=477103 for
+  # details.
+  postFixup = ''
+    $out/bin/twistd --help > /dev/null
+  '';
+
+  checkPhase = ''
+    ${python.interpreter} -m unittest discover -s twisted/test
+  '';
+  # Tests require network
+  doCheck = false;
+
+  meta = with lib; {
+    homepage = "https://twistedmatrix.com/";
+    description = "Twisted, an event-driven networking engine written in Python";
+    longDescription = ''
+      Twisted is an event-driven networking engine written in Python
+      and licensed under the MIT license.
+    '';
+    license = licenses.mit;
+    maintainers = [ ];
+  };
+}