diff --git a/stix2/__init__.py b/stix2/__init__.py
index 1747c9b..31821cf 100644
--- a/stix2/__init__.py
+++ b/stix2/__init__.py
@@ -24,8 +24,6 @@
 
 # flake8: noqa
 
-from .version import DEFAULT_VERSION
-
 from .confidence import scales
 from .datastore import CompositeDataSource
 from .datastore.filesystem import (
@@ -57,9 +55,9 @@ from .patterns import (
     RepeatQualifier, StartStopQualifier, StringConstant, TimestampConstant,
     WithinQualifier,
 )
+from .registry import _collect_stix2_mappings
 from .v21 import *  # This import will always be the latest STIX 2.X version
-from .version import __version__
+from .version import DEFAULT_VERSION, __version__
 from .versioning import new_version, revoke
 
-from .registry import _collect_stix2_mappings
 _collect_stix2_mappings()
diff --git a/stix2/registration.py b/stix2/registration.py
index 248929a..13bca74 100644
--- a/stix2/registration.py
+++ b/stix2/registration.py
@@ -2,6 +2,7 @@ import re
 
 import stix2
 import stix2.registry
+
 from .base import _DomainObject, _Observable
 from .exceptions import DuplicateRegistrationError
 from .utils import PREFIX_21_REGEX, get_class_hierarchy_names
diff --git a/stix2/registry.py b/stix2/registry.py
index 80d7cdc..6cb6cd8 100644
--- a/stix2/registry.py
+++ b/stix2/registry.py
@@ -2,7 +2,6 @@ import importlib
 import pkgutil
 import re
 
-
 # Collects information on which classes implement which STIX types, for the
 # various STIX spec versions.
 STIX2_OBJ_MAPS = {}
diff --git a/stix2/test/v20/test_custom.py b/stix2/test/v20/test_custom.py
index 77ee13d..6ce4a62 100644
--- a/stix2/test/v20/test_custom.py
+++ b/stix2/test/v20/test_custom.py
@@ -2,8 +2,8 @@ import pytest
 
 import stix2
 import stix2.parsing
-import stix2.registry
 import stix2.registration
+import stix2.registry
 import stix2.v20
 
 from ...exceptions import DuplicateRegistrationError, InvalidValueError