diff --git a/pkgs/development/python-modules/appthreat-vulnerability-db/default.nix b/pkgs/development/python-modules/appthreat-vulnerability-db/default.nix
index bedd0f367851..b248303862d5 100644
--- a/pkgs/development/python-modules/appthreat-vulnerability-db/default.nix
+++ b/pkgs/development/python-modules/appthreat-vulnerability-db/default.nix
@@ -35,6 +35,7 @@ buildPythonPackage rec {
   '';
 
   pythonRelaxDeps = [
+    "msgpack"
     "semver"
   ];