diff --git a/tasktiger/_internal.py b/tasktiger/_internal.py
index 01c913e..dc22bb6 100644
--- a/tasktiger/_internal.py
+++ b/tasktiger/_internal.py
@@ -15,13 +15,13 @@
     Iterable,
     List,
     Optional,
-    Tuple,
     Type,
     TypedDict,
     Union,
 )
 
 from .exceptions import TaskImportError
+from .types import SerializedRetryStrategy
 
 if TYPE_CHECKING:
     from .task import Task
@@ -134,7 +134,7 @@ def reversed_dotted_parts(s: str) -> Iterable[str]:
         yield s[:idx]
 
 
-def serialize_retry_method(retry_method: Any) -> Tuple[str, Tuple]:
+def serialize_retry_method(retry_method: Any) -> SerializedRetryStrategy:
     if callable(retry_method):
         return (serialize_func_name(retry_method), ())
     else:
diff --git a/tasktiger/schedule.py b/tasktiger/schedule.py
index 35aa85f..dae11bb 100644
--- a/tasktiger/schedule.py
+++ b/tasktiger/schedule.py
@@ -1,5 +1,7 @@
 import datetime
-from typing import Callable, Optional, Tuple
+from typing import Optional
+
+from .types import ScheduleStrategy
 
 __all__ = ["periodic", "cron_expr"]
 
@@ -40,7 +42,7 @@ def periodic(
     weeks: int = 0,
     start_date: Optional[datetime.datetime] = None,
     end_date: Optional[datetime.datetime] = None,
-) -> Tuple[Callable[..., Optional[datetime.datetime]], Tuple]:
+) -> ScheduleStrategy:
     """
     Periodic task schedule: Use to schedule a task to run periodically,
     starting from start_date (or None to be active immediately) until end_date
@@ -94,7 +96,7 @@ def cron_expr(
     expr: str,
     start_date: Optional[datetime.datetime] = None,
     end_date: Optional[datetime.datetime] = None,
-) -> Tuple[Callable[..., Optional[datetime.datetime]], Tuple]:
+) -> ScheduleStrategy:
     """
     Periodic task schedule via cron expression: Use to schedule a task to run periodically,
     starting from start_date (or None to be active immediately) until end_date
diff --git a/tasktiger/task.py b/tasktiger/task.py
index d5b5bb5..be4de25 100644
--- a/tasktiger/task.py
+++ b/tasktiger/task.py
@@ -32,7 +32,7 @@
 )
 from .exceptions import QueueFullException, TaskImportError, TaskNotFound
 from .runner import BaseRunner, get_runner_class
-from .types import RetryStrategy
+from .types import RetryStrategy, SerializedRetryStrategy
 
 if TYPE_CHECKING:
     from . import TaskTiger
@@ -55,9 +55,7 @@ def __init__(
         lock_key: Optional[Collection[str]] = None,
         retry: Optional[bool] = None,
         retry_on: Optional[Collection[Type[BaseException]]] = None,
-        retry_method: Optional[
-            Union[Callable[[int], float], Tuple[Callable[..., float], Tuple]]
-        ] = None,
+        retry_method: Optional[Union[Callable[[int], float], RetryStrategy]] = None,
         max_queue_size: Optional[int] = None,
         max_stored_executions: Optional[int] = None,
         runner_class: Optional[Type["BaseRunner"]] = None,
@@ -237,7 +235,7 @@ def unique_key(self) -> Optional[str]:
         return self._data.get("unique_key")
 
     @property
-    def retry_method(self) -> Optional[RetryStrategy]:
+    def retry_method(self) -> Optional[SerializedRetryStrategy]:
         if "retry_method" in self._data:
             retry_func, retry_args = self._data["retry_method"]
             return retry_func, retry_args
diff --git a/tasktiger/tasktiger.py b/tasktiger/tasktiger.py
index aeb611b..4820f3b 100644
--- a/tasktiger/tasktiger.py
+++ b/tasktiger/tasktiger.py
@@ -36,6 +36,7 @@
 from .retry import fixed
 from .runner import BaseRunner
 from .task import Task
+from .types import RetryStrategy, ScheduleStrategy
 from .worker import LOCK_REDIS_KEY, Worker
 
 __all__ = ["TaskTiger"]
@@ -312,10 +313,13 @@ def task(
         lock_key: Optional[Collection[str]] = None,
         retry: Optional[bool] = None,
         retry_on: Optional[Collection[Type[BaseException]]] = None,
-        retry_method: Optional[
-            Union[Callable[[int], float], Tuple[Callable[..., float], Tuple]]
+        retry_method: Optional[Union[Callable[[int], float], RetryStrategy]] = None,
+        schedule: Optional[
+            Union[
+                Callable[[datetime.datetime], Optional[datetime.datetime]],
+                ScheduleStrategy,
+            ]
         ] = None,
-        schedule: Optional[Callable] = None,
         batch: bool = False,
         max_queue_size: Optional[int] = None,
         max_stored_executions: Optional[int] = None,
@@ -441,9 +445,7 @@ def delay(
         when: Optional[Union[datetime.datetime, datetime.timedelta]] = None,
         retry: Optional[bool] = None,
         retry_on: Optional[Collection[Type[BaseException]]] = None,
-        retry_method: Optional[
-            Union[Callable[[int], float], Tuple[Callable[..., float], Tuple]]
-        ] = None,
+        retry_method: Optional[Union[Callable[[int], float], RetryStrategy]] = None,
         max_queue_size: Optional[int] = None,
         max_stored_executions: Optional[int] = None,
         runner_class: Optional[Type["BaseRunner"]] = None,
diff --git a/tasktiger/types.py b/tasktiger/types.py
index c0e3949..848386e 100644
--- a/tasktiger/types.py
+++ b/tasktiger/types.py
@@ -1,3 +1,9 @@
-from typing import Callable, Tuple
+import datetime
+from typing import Any, Callable, Optional, Sequence, Tuple
 
-RetryStrategy = Tuple[Callable[..., float], Tuple]
+RetryStrategy = Tuple[Callable[..., float], Tuple[Any, ...]]
+ScheduleStrategy = Tuple[Callable[..., Optional[datetime.datetime]], Tuple[Any, ...]]
+
+# A retry strategy as stored with a task. The function is replaced with its
+# import path, and the arguments come back as a list after a JSON round trip.
+SerializedRetryStrategy = Tuple[str, Sequence[Any]]