diff --git a/stdlib/2/itertools.pyi b/stdlib/2/itertools.pyi
index af7a01977..9d53e8903 100644
--- a/stdlib/2/itertools.pyi
+++ b/stdlib/2/itertools.pyi
@@ -47,6 +47,7 @@ _T1 = TypeVar('_T1')
 _T2 = TypeVar('_T2')
 _T3 = TypeVar('_T3')
 _T4 = TypeVar('_T4')
+_T5 = TypeVar('_T5')
 
 @overload
 def imap(func: Callable[[_T1], _S], iter1: Iterable[_T1]) -> Iterator[_S]: ...