diff --git a/stdlib/2.7/itertools.pyi b/stdlib/2.7/itertools.pyi
index 14ab5aecd..97623cb6c 100644
--- a/stdlib/2.7/itertools.pyi
+++ b/stdlib/2.7/itertools.pyi
@@ -18,8 +18,10 @@ def accumulate(iterable: Iterable[_T]) -> Iterator[_T]: ...
 
 class chain(Iterator[_T], Generic[_T]):
     def __init__(self, *iterables: Iterable[_T]) -> None: ...
+    def next(self) -> _T: ...
+    def __iter__(self) -> Iterator[_T]: ...
     @staticmethod
-    def from_iterable(iterable: Iterable[Iterable[_T]]) -> Iterator[_T]: ...
+    def from_iterable(iterable: Iterable[Iterable[_S]]) -> Iterator[_S]: ...
 
 def compress(data: Iterable[_T], selectors: Iterable[Any]) -> Iterator[_T]: ...
 def dropwhile(predicate: Callable[[_T], Any],
diff --git a/stdlib/3/itertools.pyi b/stdlib/3/itertools.pyi
index 6c159e330..e24bf7709 100644
--- a/stdlib/3/itertools.pyi
+++ b/stdlib/3/itertools.pyi
@@ -21,8 +21,10 @@ def accumulate(iterable: Iterable[_T]) -> Iterator[_T]: ...
 
 class chain(Iterator[_T], Generic[_T]):
     def __init__(self, *iterables: Iterable[_T]) -> None: ...
+    def __next__(self) -> _T: ...
+    def __iter__(self) -> Iterator[_T]: ...
     @staticmethod
-    def from_iterable(iterable: Iterable[Iterable[_T]]) -> Iterator[_T]: ...
+    def from_iterable(iterable: Iterable[Iterable[_S]]) -> Iterator[_S]: ...
 
 def compress(data: Iterable[_T], selectors: Iterable[Any]) -> Iterator[_T]: ...
 def dropwhile(predicate: Callable[[_T], Any],