diff --git a/fakeredis/_commands.py b/fakeredis/_commands.py
index f99b90bb..91a0ea92 100644
--- a/fakeredis/_commands.py
+++ b/fakeredis/_commands.py
@@ -8,7 +8,7 @@
 import re
 import sys
 import time
-from typing import Iterable, Tuple, Union, Optional, Any, Type, List, Callable, Sequence, Dict, Set
+from typing import Iterable, Tuple, Union, Optional, Any, Type, List, Callable, Sequence, Dict, Set, Collection
 
 from . import _msgs as msgs
 from ._helpers import null_terminate, SimpleError, Database, current_time
@@ -107,7 +107,7 @@ def __bool__(self) -> bool:
     __nonzero__ = __bool__  # For Python 2
 
 
-class Hash:  # type:ignore
+class Hash:
     DECODE_ERROR = msgs.INVALID_HASH_MSG
     redis_type = b"hash"
 
@@ -116,7 +116,7 @@ def __init__(self, *args: Any, **kwargs: Any) -> None:
         self._expirations: Dict[bytes, int] = dict()
         self._values: Dict[bytes, Any] = dict()
 
-    def _expire_keys(self):
+    def _expire_keys(self) -> None:
         removed = []
         now = current_time()
         for k in self._expirations:
@@ -154,14 +154,14 @@ def __setitem__(self, key: bytes, value: Any) -> None:
         self._expirations.pop(key, None)
         self._values[key] = value
 
-    def __delitem__(self, key):
+    def __delitem__(self, key: bytes) -> None:
         self._values.pop(key, None)
         self._expirations.pop(key, None)
 
-    def __len__(self):
+    def __len__(self) -> int:
         return len(self._values)
 
-    def __iter__(self):
+    def __iter__(self) -> Iterable[bytes]:
         return iter(self._values)
 
     def get(self, key: bytes, default: Any = None) -> Any:
@@ -425,7 +425,11 @@ def __init__(
         repeat: Tuple[Type[Union[RedisType, bytes]]] = (),  # type:ignore
         args: Tuple[str] = (),  # type:ignore
         flags: str = "",
-        server_types: Tuple[str] = ("redis", "valkey", "dragonfly"),  # supported server types: redis, dragonfly, valkey
+        server_types: Collection[str] = (
+            "redis",
+            "valkey",
+            "dragonfly",
+        ),  # supported server types: redis, dragonfly, valkey
     ):
         self.name = name
         self.func_name = func_name
diff --git a/test/test_mixins/test_set_commands.py b/test/test_mixins/test_set_commands.py
index ae624ce0..65221c47 100644
--- a/test/test_mixins/test_set_commands.py
+++ b/test/test_mixins/test_set_commands.py
@@ -12,6 +12,15 @@
 from test import testtools
 
 
+@pytest.mark.slow
+@pytest.mark.unsupported_server_types("redis", "valkey")
+def test_saddex(r: redis.Redis):
+    set_name = "foo"
+    assert testtools.raw_command(r, "saddex", set_name, 1, "m1", "m2") == 2
+    sleep(1.01)
+    assert set(r.smembers("foo")) == set()
+
+
 @testtools.run_test_if_redispy_ver("gte", "5.1")
 def test_sadd(r: redis.Redis):
     assert r.sadd("foo", "member1") == 1