diff --git a/pkgs/development/python-modules/meteoswiss-async/default.nix b/pkgs/development/python-modules/meteoswiss-async/default.nix
index b837f49c08c6..a10bbafb9d43 100644
--- a/pkgs/development/python-modules/meteoswiss-async/default.nix
+++ b/pkgs/development/python-modules/meteoswiss-async/default.nix
@@ -26,6 +26,8 @@ buildPythonPackage rec {
     hash = "sha256-xFvfyLZvBfnbzShKN+94piNUVjV1cfi4jWpc/Xw6XG4=";
   };
 
+  pythonRelaxDeps = [ "aiohttp" ];
+
   build-system = [ setuptools ];
 
   dependencies = [