diff --git a/pkgs/development/python-modules/mitmproxy/default.nix b/pkgs/development/python-modules/mitmproxy/default.nix
index 0b24d3e1a41b..cc2a56ea2544 100644
--- a/pkgs/development/python-modules/mitmproxy/default.nix
+++ b/pkgs/development/python-modules/mitmproxy/default.nix
@@ -51,6 +51,7 @@ buildPythonPackage rec {
   };
 
   pythonRelaxDeps = [
+    "h2"
     "passlib"
     "protobuf"
     "pyparsing"