diff --git a/src/linkahead/common/models.py b/src/linkahead/common/models.py
index 711b9ba66ac7e8418b178091a76aa0b6edfbf1dc..be51e268b398c9188147c7b3422a770c94c6af83 100644
--- a/src/linkahead/common/models.py
+++ b/src/linkahead/common/models.py
@@ -48,12 +48,11 @@ from os.path import isdir
 from random import randint
 from tempfile import NamedTemporaryFile
 
-from typing import TYPE_CHECKING, Dict
+from typing import TYPE_CHECKING
 
-if TYPE_CHECKING:
+if TYPE_CHECKING and sys.version_info > (3, 7):
     from datetime import datetime
-    from typing import Any, Literal, Optional, Type, Union, List, TextIO, Tuple
-
+    from typing import Any, Dict, Optional, Type, Union, List, TextIO, Tuple, Literal
 
 from warnings import warn
 
@@ -4306,7 +4305,7 @@ class ACL():
 
     def grant(
         self,
-        permission: str,
+        permission: Optional[str],
         username: Optional[str] = None,
         realm: Optional[str] = None,
         role: Optional[str] = None,