diff --git a/nonebot/plugin/on.py b/nonebot/plugin/on.py
index 6136b7ba..2340255d 100644
--- a/nonebot/plugin/on.py
+++ b/nonebot/plugin/on.py
@@ -238,7 +238,7 @@ def on_request(
 
 def on_startswith(
     msg: Union[str, Tuple[str, ...]],
-    rule: Optional[Optional[Union[Rule, T_RuleChecker]]] = None,
+    rule: Optional[Union[Rule, T_RuleChecker]] = None,
     ignorecase: bool = False,
     _depth: int = 0,
     **kwargs,
@@ -262,7 +262,7 @@ def on_startswith(
 
 def on_endswith(
     msg: Union[str, Tuple[str, ...]],
-    rule: Optional[Optional[Union[Rule, T_RuleChecker]]] = None,
+    rule: Optional[Union[Rule, T_RuleChecker]] = None,
     ignorecase: bool = False,
     _depth: int = 0,
     **kwargs,
@@ -286,7 +286,7 @@ def on_endswith(
 
 def on_fullmatch(
     msg: Union[str, Tuple[str, ...]],
-    rule: Optional[Optional[Union[Rule, T_RuleChecker]]] = None,
+    rule: Optional[Union[Rule, T_RuleChecker]] = None,
     ignorecase: bool = False,
     _depth: int = 0,
     **kwargs,
diff --git a/nonebot/plugin/on.pyi b/nonebot/plugin/on.pyi
index 6011eb43..9b2393f1 100644
--- a/nonebot/plugin/on.pyi
+++ b/nonebot/plugin/on.pyi
@@ -57,7 +57,7 @@ def on_request(
 ) -> Type[Matcher]: ...
 def on_startswith(
     msg: Union[str, Tuple[str, ...]],
-    rule: Optional[Optional[Union[Rule, T_RuleChecker]]] = ...,
+    rule: Optional[Union[Rule, T_RuleChecker]] = ...,
     ignorecase: bool = ...,
     *,
     permission: Optional[Union[Permission, T_PermissionChecker]] = ...,
@@ -69,7 +69,7 @@ def on_startswith(
 ) -> Type[Matcher]: ...
 def on_endswith(
     msg: Union[str, Tuple[str, ...]],
-    rule: Optional[Optional[Union[Rule, T_RuleChecker]]] = ...,
+    rule: Optional[Union[Rule, T_RuleChecker]] = ...,
     ignorecase: bool = ...,
     *,
     permission: Optional[Union[Permission, T_PermissionChecker]] = ...,
@@ -81,7 +81,7 @@ def on_endswith(
 ) -> Type[Matcher]: ...
 def on_fullmatch(
     msg: Union[str, Tuple[str, ...]],
-    rule: Optional[Optional[Union[Rule, T_RuleChecker]]] = ...,
+    rule: Optional[Union[Rule, T_RuleChecker]] = ...,
     ignorecase: bool = ...,
     *,
     permission: Optional[Union[Permission, T_PermissionChecker]] = ...,