namespace-typing: fix invalid types

Change-Id: I4e38226c95b9204a05403e5d95713234e9f903d8
---
M pywikibot/site/_namespace.py
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/pywikibot/site/_namespace.py b/pywikibot/site/_namespace.py
index 9a52e73..1618449 100644
--- a/pywikibot/site/_namespace.py
+++ b/pywikibot/site/_namespace.py
@@ -8,12 +8,13 @@
 from enum import IntEnum
 from typing import Optional, Union
 
+from pywikibot.backports import Iterable as IterableType
 from pywikibot.backports import List
 from pywikibot.tools import ComparableMixin, SelfCallMixin
 
 
-NamespaceIDType = 'Union[int, str, Namespace]'
-NamespaceArgType = 'Union[NamespaceIDType, Iterable[NamespaceIDType], None]'
+NamespaceIDType = Union[int, str, 'Namespace']
+NamespaceArgType = Union[NamespaceIDType, IterableType[NamespaceIDType], None]
 
 
 class BuiltinNamespace(IntEnum):

