diff --git a/redis/asyncio/lock.py b/redis/asyncio/lock.py
index 16d7fb6957..5376dbf7e6 100644
--- a/redis/asyncio/lock.py
+++ b/redis/asyncio/lock.py
@@ -3,7 +3,7 @@
 import threading
 import uuid
 from types import SimpleNamespace
-from typing import TYPE_CHECKING, Awaitable, Optional, Union
+from typing import TYPE_CHECKING, Awaitable, Literal, Optional, Union
 
 from redis.exceptions import LockError, LockNotOwnedError
 from redis.typing import Number
@@ -284,7 +284,7 @@ async def do_release(self, expected_token: bytes) -> None:
 
     def extend(
         self, additional_time: Number, replace_ttl: bool = False
-    ) -> Awaitable[bool]:
+    ) -> Awaitable[Literal[True]]:
         """
         Adds more time to an already acquired lock.
 
@@ -301,7 +301,7 @@ def extend(
             raise LockError("Cannot extend a lock with no timeout")
         return self.do_extend(additional_time, replace_ttl)
 
-    async def do_extend(self, additional_time, replace_ttl) -> bool:
+    async def do_extend(self, additional_time, replace_ttl) -> Literal[True]:
         additional_time = int(additional_time * 1000)
         if not bool(
             await self.lua_extend(
diff --git a/redis/lock.py b/redis/lock.py
index 0288496e6f..8602e0aa06 100644
--- a/redis/lock.py
+++ b/redis/lock.py
@@ -3,7 +3,7 @@
 import time as mod_time
 import uuid
 from types import SimpleNamespace, TracebackType
-from typing import Optional, Type
+from typing import Literal, Optional, Type
 
 from redis.exceptions import LockError, LockNotOwnedError
 from redis.typing import Number
@@ -284,7 +284,7 @@ def do_release(self, expected_token: str) -> None:
                 lock_name=self.name,
             )
 
-    def extend(self, additional_time: Number, replace_ttl: bool = False) -> bool:
+    def extend(self, additional_time: Number, replace_ttl: bool = False) -> Literal[True]:
         """
         Adds more time to an already acquired lock.
 
@@ -301,7 +301,7 @@ def extend(self, additional_time: Number, replace_ttl: bool = False) -> bool:
             raise LockError("Cannot extend a lock with no timeout", lock_name=self.name)
         return self.do_extend(additional_time, replace_ttl)
 
-    def do_extend(self, additional_time: Number, replace_ttl: bool) -> bool:
+    def do_extend(self, additional_time: Number, replace_ttl: bool) -> Literal[True]:
         additional_time = int(additional_time * 1000)
         if not bool(
             self.lua_extend(