diff --git a/CHANGES b/CHANGES
index bd96846b6d..031d909f23 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,4 @@
+    * Fix lock.extend() typedef to accept float TTL extension
     * Update URL in the readme linking to Redis University
     * Move doctests (doc code examples) to main branch
     * Update `ResponseT` type hint
diff --git a/redis/asyncio/lock.py b/redis/asyncio/lock.py
index bb2cccab52..f70a8d09ab 100644
--- a/redis/asyncio/lock.py
+++ b/redis/asyncio/lock.py
@@ -5,6 +5,7 @@
 from typing import TYPE_CHECKING, Awaitable, Optional, Union
 
 from redis.exceptions import LockError, LockNotOwnedError
+from redis.typing import Number
 
 if TYPE_CHECKING:
     from redis.asyncio import Redis, RedisCluster
@@ -82,7 +83,7 @@ def __init__(
         timeout: Optional[float] = None,
         sleep: float = 0.1,
         blocking: bool = True,
-        blocking_timeout: Optional[float] = None,
+        blocking_timeout: Optional[Number] = None,
         thread_local: bool = True,
     ):
         """
@@ -167,7 +168,7 @@ async def __aexit__(self, exc_type, exc_value, traceback):
     async def acquire(
         self,
         blocking: Optional[bool] = None,
-        blocking_timeout: Optional[float] = None,
+        blocking_timeout: Optional[Number] = None,
         token: Optional[Union[str, bytes]] = None,
     ):
         """
@@ -265,7 +266,7 @@ async def do_release(self, expected_token: bytes) -> None:
             raise LockNotOwnedError("Cannot release a lock that's no longer owned")
 
     def extend(
-        self, additional_time: float, replace_ttl: bool = False
+        self, additional_time: Number, replace_ttl: bool = False
     ) -> Awaitable[bool]:
         """
         Adds more time to an already acquired lock.
diff --git a/tests/test_asyncio/test_lock.py b/tests/test_asyncio/test_lock.py
index 033a8b7467..9973ef701f 100644
--- a/tests/test_asyncio/test_lock.py
+++ b/tests/test_asyncio/test_lock.py
@@ -174,11 +174,12 @@ async def test_extend_lock_replace_ttl(self, r):
         await lock.release()
 
     async def test_extend_lock_float(self, r):
-        lock = self.get_lock(r, "foo", timeout=10.0)
+        lock = self.get_lock(r, "foo", timeout=10.5)
         assert await lock.acquire(blocking=False)
-        assert 8000 < (await r.pttl("foo")) <= 10000
-        assert await lock.extend(10.0)
-        assert 16000 < (await r.pttl("foo")) <= 20000
+        assert 10400 < (await r.pttl("foo")) <= 10500
+        old_ttl = await r.pttl("foo")
+        assert await lock.extend(10.5)
+        assert old_ttl + 10400 < (await r.pttl("foo")) <= old_ttl + 10500
         await lock.release()
 
     async def test_extending_unlocked_lock_raises_error(self, r):
diff --git a/tests/test_lock.py b/tests/test_lock.py
index d77ff9717a..136c86e459 100644
--- a/tests/test_lock.py
+++ b/tests/test_lock.py
@@ -178,11 +178,12 @@ def test_extend_lock_replace_ttl(self, r):
         lock.release()
 
     def test_extend_lock_float(self, r):
-        lock = self.get_lock(r, "foo", timeout=10.0)
+        lock = self.get_lock(r, "foo", timeout=10.5)
         assert lock.acquire(blocking=False)
-        assert 8000 < r.pttl("foo") <= 10000
-        assert lock.extend(10.0)
-        assert 16000 < r.pttl("foo") <= 20000
+        assert 10400 < r.pttl("foo") <= 10500
+        old_ttl = r.pttl("foo")
+        assert lock.extend(10.5)
+        assert old_ttl + 10400 < r.pttl("foo") <= old_ttl + 10500
         lock.release()
 
     def test_extending_unlocked_lock_raises_error(self, r):