diff --git a/stdlib/2.7/datetime.pyi b/stdlib/2.7/datetime.pyi
index 44699f306..4488e7f9c 100644
--- a/stdlib/2.7/datetime.pyi
+++ b/stdlib/2.7/datetime.pyi
@@ -198,7 +198,7 @@ class datetime(object):
     def replace(self, year: int = ..., month: int = ..., day: int = ..., hour: int = ...,
                 minute: int = ..., second: int = ..., microsecond: int = ..., tzinfo:
                 Union[_tzinfo, bool] = ...) -> datetime: ...
-    def astimezone(self, tz: timezone = ...) -> datetime: ...
+    def astimezone(self, tz: _tzinfo = ...) -> datetime: ...
     def ctime(self) -> str: ...
     def isoformat(self, sep: str = ...) -> str: ...
     @classmethod
diff --git a/stdlib/3/datetime.pyi b/stdlib/3/datetime.pyi
index 4d8efb8b8..c0ee98b47 100644
--- a/stdlib/3/datetime.pyi
+++ b/stdlib/3/datetime.pyi
@@ -198,7 +198,7 @@ class datetime:
     def replace(self, year: int = ..., month: int = ..., day: int = ..., hour: int = ...,
                 minute: int = ..., second: int = ..., microsecond: int = ..., tzinfo:
                 Union[_tzinfo, bool] = ...) -> datetime: ...
-    def astimezone(self, tz: timezone = ...) -> datetime: ...
+    def astimezone(self, tz: _tzinfo = ...) -> datetime: ...
     def ctime(self) -> str: ...
     def isoformat(self, sep: str = ...) -> str: ...
     @classmethod