diff --git a/pkgs/development/python-modules/qcs-api-client/default.nix b/pkgs/development/python-modules/qcs-api-client/default.nix
index 34984ec5755e..9d903f4fe064 100644
--- a/pkgs/development/python-modules/qcs-api-client/default.nix
+++ b/pkgs/development/python-modules/qcs-api-client/default.nix
@@ -50,6 +50,7 @@ buildPythonPackage rec {
     "httpx"
     "iso8601"
     "pydantic"
+    "tenacity"
   ];
 
   build-system = [ poetry-core ];