diff --git a/stix2/versioning.py b/stix2/versioning.py
index fc8bc7d..01affe9 100644
--- a/stix2/versioning.py
+++ b/stix2/versioning.py
@@ -1,12 +1,11 @@
 """STIX2 core versioning methods."""
 
+from collections.abc import Mapping
 import copy
 import datetime as dt
 import itertools
 import uuid
 
-from collections.abc import Mapping
-
 import stix2.base
 import stix2.registry
 from stix2.utils import (