diff --git a/cachebox/_cachebox.py b/cachebox/_cachebox.py
index def0a30..9beaff0 100644
--- a/cachebox/_cachebox.py
+++ b/cachebox/_cachebox.py
@@ -161,16 +161,15 @@ def __init__(
         )
 
         self._thread: threading.Thread | None = None
-        self._thread_is_running: bool = False
+        self._stop_event = threading.Event()
 
         if sweep_interval is not None:
             if isinstance(sweep_interval, timedelta):
                 sweep_interval = sweep_interval.total_seconds()
 
             if sweep_interval < 1:
-                raise ValueError("sweep_interval must be more than 1 seconds.")
+                raise ValueError("sweep_interval must be at least 1 second.")
 
-            self._thread_is_running = True
             self._thread = threading.Thread(
                 target=self._sweeper_thread,
                 args=(sweep_interval,),
@@ -185,14 +184,13 @@ def sweep_interval(self) -> float | None:
         """The configured ``sweep_interval`` in seconds."""
         return self._sweep_interval
 
-    def _sweeper_thread(self, interval: float):
-        while self._thread_is_running:
-            time.sleep(interval)
+    def _sweeper_thread(self, interval: float) -> None:
+        while not self._stop_event.wait(interval):
             self.expire()
 
     def stop_sweeper(self) -> None:
         """Signals the background sweeper thread to stop, if one is active."""
-        self._thread_is_running = False
+        self._stop_event.set()
 
     def __del__(self) -> None:
         self.stop_sweeper()
@@ -333,16 +331,15 @@ def __init__(
         )
 
         self._thread: threading.Thread | None = None
-        self._thread_is_running: bool = False
+        self._stop_event = threading.Event()
 
         if sweep_interval is not None:
             if isinstance(sweep_interval, timedelta):
                 sweep_interval = sweep_interval.total_seconds()
 
             if sweep_interval < 1:
-                raise ValueError("sweep_interval must be more than 1 seconds.")
+                raise ValueError("sweep_interval must be at least 1 second.")
 
-            self._thread_is_running = True
             self._thread = threading.Thread(
                 target=self._sweeper_thread,
                 args=(sweep_interval,),
@@ -357,14 +354,13 @@ def sweep_interval(self) -> float | None:
         """The configured ``sweep_interval`` in seconds."""
         return self._sweep_interval
 
-    def _sweeper_thread(self, interval: float):
-        while self._thread_is_running:
-            time.sleep(interval)
+    def _sweeper_thread(self, interval: float) -> None:
+        while not self._stop_event.wait(interval):
             self.expire()
 
     def stop_sweeper(self) -> None:
         """Signals the background sweeper thread to stop, if one is active."""
-        self._thread_is_running = False
+        self._stop_event.set()
 
     def __del__(self) -> None:
         self.stop_sweeper()
diff --git a/cachebox/_wrappers.py b/cachebox/_wrappers.py
index 14c4a8f..ed81393 100644
--- a/cachebox/_wrappers.py
+++ b/cachebox/_wrappers.py
@@ -2,12 +2,14 @@
 import typing
 from collections import namedtuple
 from contextlib import AbstractAsyncContextManager, AbstractContextManager
+from collections.abc import Callable, Hashable
 
 from cachebox._core import BaseCacheImpl, Cache
 
-_PostProcess: typing.TypeAlias = typing.Callable[[typing.Any], typing.Any]
-_Callback: typing.TypeAlias = typing.Callable[[int, typing.Any, typing.Any], typing.Any]
-
+_PostProcess: typing.TypeAlias = Callable[[typing.Any], typing.Any]
+_Callback: typing.TypeAlias = Callable[
+    [int, typing.Any, typing.Any], typing.Any
+]
 
 class _Lock:
     __slots__ = ("_lock", "waiters")
@@ -65,10 +67,10 @@ def _create_cache_info(cache, hits, misses) -> CacheInfo:
 
 def _cached_wrapper_without_lock(
     func,
-    cache: BaseCacheImpl | typing.Callable,
-    key_maker: typing.Callable[[tuple, dict], typing.Hashable],
+    cache: BaseCacheImpl | Callable,
+    key_maker: Callable[[tuple, dict], Hashable],
     clear_reuse: bool,
-    callback: typing.Callable[[int, typing.Any, typing.Any], None] | None,
+    callback: Callable[[int, typing.Any, typing.Any], None] | None,
     postprocess: _PostProcess | None,
 ):
     cache_is_fn = callable(cache)
@@ -139,10 +141,10 @@ async def _call_async_callback(callback, event, key, result):
 
 def _async_cached_wrapper_without_lock(
     func,
-    cache: BaseCacheImpl | typing.Callable,
-    key_maker: typing.Callable[[tuple, dict], typing.Hashable],
+    cache: BaseCacheImpl | Callable,
+    key_maker: Callable[[tuple, dict], Hashable],
     clear_reuse: bool,
-    callback: typing.Callable[[int, typing.Any, typing.Any], None] | None,
+    callback: Callable[[int, typing.Any, typing.Any], None] | None,
     postprocess: _PostProcess | None,
 ):
     cache_is_fn = callable(cache)
@@ -179,7 +181,7 @@ async def _wrapped(*args, **kwds):
 
         result = await func(*args, **kwds)
         _cache.insert(key, result)
-        hits += 1
+        misses += 1
         await _call_async_callback(callback, EVENT_MISS, key, result)
 
         return postprocess(result) if postprocess is not None else result
@@ -202,12 +204,12 @@ def cache_clear() -> None:
 
 def _cached_wrapper(
     func,
-    cache: BaseCacheImpl | typing.Callable,
-    key_maker: typing.Callable[[tuple, dict], typing.Hashable],
+    cache: BaseCacheImpl | Callable,
+    key_maker: Callable[[tuple, dict], Hashable],
     clear_reuse: bool,
-    callback: typing.Callable[[int, typing.Any, typing.Any], None] | None,
+    callback: Callable[[int, typing.Any, typing.Any], None] | None,
     postprocess: _PostProcess | None,
-    lock_type: typing.Type[AbstractContextManager],
+    lock_type: type[AbstractContextManager],
 ):
     cache_is_fn = callable(cache)
 
@@ -221,8 +223,8 @@ def _cached_wrapper(
     hits = 0
     misses = 0
 
-    locks: Cache[typing.Hashable, _Lock] = Cache(0)
-    pending_errors: dict[typing.Hashable, BaseException] = {}
+    locks: Cache[Hashable, _Lock] = Cache(0)
+    pending_errors: dict[Hashable, BaseException] = {}
 
     def _wrapped(*args, **kwds):
         nonlocal hits, misses
@@ -308,12 +310,12 @@ def cache_clear() -> None:
 
 def _async_cached_wrapper(
     func,
-    cache: BaseCacheImpl | typing.Callable,
+    cache: BaseCacheImpl | Callable,
     key_maker: typing.Callable[..., typing.Hashable],
     clear_reuse: bool,
     callback: _Callback | None,
     postprocess: _PostProcess | None,
-    lock_type: typing.Type[AbstractAsyncContextManager],
+    lock_type: type[AbstractAsyncContextManager],
 ):
     cache_is_fn = callable(cache)
     _make_key = (