diff --git a/lso/routes/playbook.py b/lso/routes/playbook.py
index 00a41e2..437c3be 100644
--- a/lso/routes/playbook.py
+++ b/lso/routes/playbook.py
@@ -43,8 +43,8 @@ def _inventory_validator(inventory: dict[str, Any] | str) -> dict[str, Any] | st
     :raises HTTPException: If parsing fails or the format is incorrect.
     """
     if not ansible_runner.utils.isinventory(inventory):
-        error_messages = "Invalid inventory provided. Should be a string, or JSON object."
-        raise HTTPException(status_code=status.HTTP_422_UNPROCESSABLE_ENTITY, detail=error_messages)
+        detail = "Invalid inventory provided. Should be a string, or JSON object."
+        raise HTTPException(status_code=status.HTTP_422_UNPROCESSABLE_ENTITY, detail=detail)
 
     loader = DataLoader()
     output = StringIO()