diff --git a/pkgs/development/python-modules/mitmproxy/default.nix b/pkgs/development/python-modules/mitmproxy/default.nix
index 93a77b49a8e2..be1d7f8f23fb 100644
--- a/pkgs/development/python-modules/mitmproxy/default.nix
+++ b/pkgs/development/python-modules/mitmproxy/default.nix
@@ -57,8 +57,8 @@ buildPythonPackage rec {
     hash = "sha256-f5TudaLlHtIMAvS7s5mWgqpdi7/vWNF0EdlYNuG67hM=";
   };
 
-
   pythonRelaxDeps = [
+    "passlib"
     "protobuf"
     "urwid"
   ];