diff --git a/backend/config.py b/backend/config.py
index 281aea2a4..feb65305b 100644
--- a/backend/config.py
+++ b/backend/config.py
@@ -289,8 +289,12 @@ DEFAULT_PROMPT_SUGGESTIONS = (
 
 DEFAULT_USER_ROLE = os.getenv("DEFAULT_USER_ROLE", "pending")
 
-USER_PERMISSIONS_CHAT_DELETION = os.getenv('USER_PERMISSIONS_CHAT_DELETION', 'True') == 'True'
-USER_PERMISSIONS = {"chat": {"deletion": USER_PERMISSIONS_CHAT_DELETION}}
+USER_PERMISSIONS_CHAT_DELETION = os.getenv('USER_PERMISSIONS_CHAT_DELETION', 'True')
+
+if USER_PERMISSIONS_CHAT_DELETION not in ('True', 'False'):
+    raise ValueError(ERROR_MESSAGES.INCORRECT_FORMAT("  (e.g., True/False)."))
+
+USER_PERMISSIONS = {"chat": {"deletion": USER_PERMISSIONS_CHAT_DELETION == 'True'}}
 
 
 MODEL_FILTER_ENABLED = os.environ.get("MODEL_FILTER_ENABLED", False)
diff --git a/backend/constants.py b/backend/constants.py
index eacf8a20f..55e0bcce8 100644
--- a/backend/constants.py
+++ b/backend/constants.py
@@ -46,7 +46,7 @@ class ERROR_MESSAGES(str, Enum):
 
     PANDOC_NOT_INSTALLED = "Pandoc is not installed on the server. Please contact your administrator for assistance."
     INCORRECT_FORMAT = (
-        lambda err="": f"Invalid format. Please use the correct format{err if err else ''}"
+        lambda err="": f"Invalid format. Please use the correct format{err}"
     )
     RATE_LIMIT_EXCEEDED = "API rate limit exceeded"