diff --git a/stdlib/2and3/plistlib.pyi b/stdlib/2and3/plistlib.pyi
index 62668821b..4db0730a6 100644
--- a/stdlib/2and3/plistlib.pyi
+++ b/stdlib/2and3/plistlib.pyi
@@ -22,29 +22,41 @@ if sys.version_info >= (3,):
 else:
     _Path = Union[str, unicode]
 
-if sys.version_info >= (3, 4):
+if sys.version_info >= (3, 9):
+    @overload
+    def load(fp: IO[bytes], *, fmt: Optional[PlistFormat] = ...) -> DictT[str, Any]: ...
+    @overload
+    def load(fp: IO[bytes], *, fmt: Optional[PlistFormat] = ..., dict_type: Type[_D]) -> _D: ...
+    @overload
+    def loads(value: bytes, *, fmt: Optional[PlistFormat] = ...) -> DictT[str, Any]: ...
+    @overload
+    def loads(value: bytes, *, fmt: Optional[PlistFormat] = ..., dict_type: Type[_D]) -> _D: ...
+elif sys.version_info >= (3, 4):
     @overload
     def load(fp: IO[bytes], *, fmt: Optional[PlistFormat] = ...,
              use_builtin_types: bool = ...) -> DictT[str, Any]: ...
     @overload
     def load(fp: IO[bytes], *, fmt: Optional[PlistFormat] = ...,
-             use_builtin_types: bool = ..., dict_type: Type[_D] = ...) -> _D: ...
+             use_builtin_types: bool = ..., dict_type: Type[_D]) -> _D: ...
     @overload
     def loads(value: bytes, *, fmt: Optional[PlistFormat] = ...,
               use_builtin_types: bool = ...) -> DictT[str, Any]: ...
     @overload
     def loads(value: bytes, *, fmt: Optional[PlistFormat] = ...,
-              use_builtin_types: bool = ..., dict_type: Type[_D] = ...) -> _D: ...
+              use_builtin_types: bool = ..., dict_type: Type[_D]) -> _D: ...
+
+if sys.version_info >= (3, 4):
     def dump(value: Mapping[str, Any], fp: IO[bytes], *,
              fmt: PlistFormat = ..., sort_keys: bool = ...,
              skipkeys: bool = ...) -> None: ...
     def dumps(value: Mapping[str, Any], *, fmt: PlistFormat = ...,
               skipkeys: bool = ..., sort_keys: bool = ...) -> bytes: ...
 
-def readPlist(pathOrFile: Union[_Path, IO[bytes]]) -> DictT[str, Any]: ...
-def writePlist(value: Mapping[str, Any], pathOrFile: Union[_Path, IO[bytes]]) -> None: ...
-def readPlistFromBytes(data: bytes) -> DictT[str, Any]: ...
-def writePlistToBytes(value: Mapping[str, Any]) -> bytes: ...
+if sys.version_info < (3, 9):
+    def readPlist(pathOrFile: Union[_Path, IO[bytes]]) -> DictT[str, Any]: ...
+    def writePlist(value: Mapping[str, Any], pathOrFile: Union[_Path, IO[bytes]]) -> None: ...
+    def readPlistFromBytes(data: bytes) -> DictT[str, Any]: ...
+    def writePlistToBytes(value: Mapping[str, Any]) -> bytes: ...
 if sys.version_info < (3,):
     def readPlistFromResource(path: _Path, restype: str = ...,
                               resid: int = ...) -> DictT[str, Any]: ...
@@ -60,9 +72,10 @@ if sys.version_info < (3, 7):
         def __setattr__(self, attr: str, value: Any) -> None: ...
         def __delattr__(self, attr: str) -> None: ...
 
-class Data:
-    data: bytes
-    def __init__(self, data: bytes) -> None: ...
+if sys.version_info < (3, 9):
+    class Data:
+        data: bytes
+        def __init__(self, data: bytes) -> None: ...
 
 if sys.version_info >= (3, 8):
     class UID: