Use Py_ssize_t for counts and sizes.
Convert Py_ssize_t using PyInt_FromSsize_t
diff --git a/Objects/iterobject.c b/Objects/iterobject.c
index 6f7c57e..51f551b 100644
--- a/Objects/iterobject.c
+++ b/Objects/iterobject.c
@@ -82,7 +82,7 @@
 			return NULL;
 		len = seqsize - it->it_index;
 		if (len >= 0)
-			return PyInt_FromLong(len);
+			return PyInt_FromSsize_t(len);
 	}
 	return PyInt_FromLong(0);
 }