diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 309e53b..3dba8ef 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -6,3 +6,8 @@
         args:
         - --max-line-length=160
     -   id: check-merge-conflict
+
+- repo: https://github.com/FalconSocial/pre-commit-python-sorter
+  sha: 1.0.4
+  hooks:
+  - id: python-import-sorter
diff --git a/stix2/__init__.py b/stix2/__init__.py
index 84560ad..a3595d2 100644
--- a/stix2/__init__.py
+++ b/stix2/__init__.py
@@ -2,20 +2,20 @@
 
 # flake8: noqa
 
+from . import exceptions
 from .bundle import Bundle
-from .observables import Artifact, AutonomousSystem, Directory, DomainName, \
-    EmailAddress, EmailMessage, File, IPv4Address, IPv6Address, MACAddress, \
-    Mutex, NetworkTraffic, Process, Software, URL, UserAccount, WindowsRegistryKey, \
-    X509Certificate
-from .other import ExternalReference, KillChainPhase, MarkingDefinition, \
-    GranularMarking, StatementMarking, TLPMarking
-from .sdo import AttackPattern, Campaign, CourseOfAction, Identity, Indicator, \
-    IntrusionSet, Malware, ObservedData, Report, ThreatActor, Tool, \
-    Vulnerability
+from .observables import (URL, Artifact, AutonomousSystem, Directory,
+                          DomainName, EmailAddress, EmailMessage, File,
+                          IPv4Address, IPv6Address, MACAddress, Mutex,
+                          NetworkTraffic, Process, Software, UserAccount,
+                          WindowsRegistryKey, X509Certificate)
+from .other import (ExternalReference, GranularMarking, KillChainPhase,
+                    MarkingDefinition, StatementMarking, TLPMarking)
+from .sdo import (AttackPattern, Campaign, CourseOfAction, Identity, Indicator,
+                  IntrusionSet, Malware, ObservedData, Report, ThreatActor,
+                  Tool, Vulnerability)
 from .sro import Relationship, Sighting
 from .utils import get_dict
-from . import exceptions
-
 
 OBJ_MAP = {
     'attack-pattern': AttackPattern,
diff --git a/stix2/base.py b/stix2/base.py
index f9c4391..a99805c 100644
--- a/stix2/base.py
+++ b/stix2/base.py
@@ -3,14 +3,12 @@
 import collections
 import copy
 import datetime as dt
-
 import json
 
-
-from .exceptions import ExtraFieldsError, ImmutableError, InvalidObjRefError, \
-                        InvalidValueError, MissingFieldsError, RevokeError, \
-                        UnmodifiablePropertyError
-from .utils import format_datetime, get_timestamp, NOW, parse_into_datetime
+from .exceptions import (ExtraFieldsError, ImmutableError, InvalidObjRefError,
+                         InvalidValueError, MissingFieldsError, RevokeError,
+                         UnmodifiablePropertyError)
+from .utils import NOW, format_datetime, get_timestamp, parse_into_datetime
 
 __all__ = ['STIXJSONEncoder', '_STIXBase']
 
diff --git a/stix2/other.py b/stix2/other.py
index 9b7f03a..7b58c0b 100644
--- a/stix2/other.py
+++ b/stix2/other.py
@@ -4,7 +4,7 @@ from .base import _STIXBase
 from .properties import (IDProperty, ListProperty, Property, ReferenceProperty,
                          SelectorProperty, StringProperty, TimestampProperty,
                          TypeProperty)
-from .utils import get_dict, NOW
+from .utils import NOW, get_dict
 
 
 class ExternalReference(_STIXBase):
diff --git a/stix2/properties.py b/stix2/properties.py
index 9e4ad9e..5b0a677 100644
--- a/stix2/properties.py
+++ b/stix2/properties.py
@@ -5,12 +5,10 @@ import datetime as dt
 import inspect
 import re
 import uuid
-
-from dateutil import parser
-import pytz
 from six import text_type
-
-from .base import _STIXBase, Observable
+import pytz
+from dateutil import parser
+from .base import Observable, _STIXBase
 from .exceptions import DictionaryKeyError
 
 
diff --git a/stix2/test/conftest.py b/stix2/test/conftest.py
index ec967b5..d1f3330 100644
--- a/stix2/test/conftest.py
+++ b/stix2/test/conftest.py
@@ -5,8 +5,8 @@ import pytest
 
 import stix2
 
-from .constants import FAKE_TIME
-from .constants import INDICATOR_KWARGS, MALWARE_KWARGS, RELATIONSHIP_KWARGS
+from .constants import (FAKE_TIME, INDICATOR_KWARGS, MALWARE_KWARGS,
+                        RELATIONSHIP_KWARGS)
 
 
 # Inspired by: http://stackoverflow.com/a/24006251
diff --git a/stix2/test/test_attack_pattern.py b/stix2/test/test_attack_pattern.py
index c0891a5..fe399a1 100644
--- a/stix2/test/test_attack_pattern.py
+++ b/stix2/test/test_attack_pattern.py
@@ -2,10 +2,12 @@ import datetime as dt
 
 import pytest
 import pytz
+
 import stix2
 
 from .constants import ATTACK_PATTERN_ID
 
+
 EXPECTED = """{
     "created": "2016-05-12T08:17:27Z",
     "description": "...",
diff --git a/stix2/test/test_bundle.py b/stix2/test/test_bundle.py
index 6386a66..a849f3e 100644
--- a/stix2/test/test_bundle.py
+++ b/stix2/test/test_bundle.py
@@ -2,6 +2,7 @@ import pytest
 
 import stix2
 
+
 EXPECTED_BUNDLE = """{
     "id": "bundle--00000000-0000-0000-0000-000000000004",
     "objects": [
diff --git a/stix2/test/test_campaign.py b/stix2/test/test_campaign.py
index 7f6c4e6..9920019 100644
--- a/stix2/test/test_campaign.py
+++ b/stix2/test/test_campaign.py
@@ -2,10 +2,12 @@ import datetime as dt
 
 import pytest
 import pytz
+
 import stix2
 
 from .constants import CAMPAIGN_ID
 
+
 EXPECTED = """{
     "created": "2016-04-06T20:03:00Z",
     "created_by_ref": "identity--f431f809-377b-45e0-aa1c-6a4751cae5ff",
diff --git a/stix2/test/test_course_of_action.py b/stix2/test/test_course_of_action.py
index f566e10..263eae2 100644
--- a/stix2/test/test_course_of_action.py
+++ b/stix2/test/test_course_of_action.py
@@ -2,10 +2,12 @@ import datetime as dt
 
 import pytest
 import pytz
+
 import stix2
 
 from .constants import COURSE_OF_ACTION_ID
 
+
 EXPECTED = """{
     "created": "2016-04-06T20:03:48Z",
     "created_by_ref": "identity--f431f809-377b-45e0-aa1c-6a4751cae5ff",
diff --git a/stix2/test/test_external_reference.py b/stix2/test/test_external_reference.py
index 1e25fd2..3470bd4 100644
--- a/stix2/test/test_external_reference.py
+++ b/stix2/test/test_external_reference.py
@@ -3,8 +3,10 @@
 import re
 
 import pytest
+
 import stix2
 
+
 VERIS = """{
     "external_id": "0001AA7F-C601-424A-B2B8-BE6C9F5164E7",
     "source_name": "veris",
diff --git a/stix2/test/test_identity.py b/stix2/test/test_identity.py
index 41c87bb..3952d25 100644
--- a/stix2/test/test_identity.py
+++ b/stix2/test/test_identity.py
@@ -2,10 +2,12 @@ import datetime as dt
 
 import pytest
 import pytz
+
 import stix2
 
 from .constants import IDENTITY_ID
 
+
 EXPECTED = """{
     "created": "2015-12-21T19:59:11Z",
     "id": "identity--311b2d2d-f010-5473-83ec-1edf84858f4c",
diff --git a/stix2/test/test_indicator.py b/stix2/test/test_indicator.py
index baf4b38..3e865b2 100644
--- a/stix2/test/test_indicator.py
+++ b/stix2/test/test_indicator.py
@@ -3,10 +3,12 @@ import re
 
 import pytest
 import pytz
+
 import stix2
 
 from .constants import FAKE_TIME, INDICATOR_ID, INDICATOR_KWARGS
 
+
 EXPECTED_INDICATOR = """{
     "created": "2017-01-01T00:00:01Z",
     "id": "indicator--01234567-89ab-cdef-0123-456789abcdef",
diff --git a/stix2/test/test_intrusion_set.py b/stix2/test/test_intrusion_set.py
index 19fb641..3241ced 100644
--- a/stix2/test/test_intrusion_set.py
+++ b/stix2/test/test_intrusion_set.py
@@ -2,10 +2,12 @@ import datetime as dt
 
 import pytest
 import pytz
+
 import stix2
 
 from .constants import INTRUSION_SET_ID
 
+
 EXPECTED = """{
     "aliases": [
         "Zookeeper"
diff --git a/stix2/test/test_kill_chain_phases.py b/stix2/test/test_kill_chain_phases.py
index 037e930..92dfd66 100644
--- a/stix2/test/test_kill_chain_phases.py
+++ b/stix2/test/test_kill_chain_phases.py
@@ -4,6 +4,7 @@ import pytest
 
 import stix2
 
+
 LMCO_RECON = """{
     "kill_chain_name": "lockheed-martin-cyber-kill-chain",
     "phase_name": "reconnaissance"
diff --git a/stix2/test/test_malware.py b/stix2/test/test_malware.py
index f3bfccd..9874a3c 100644
--- a/stix2/test/test_malware.py
+++ b/stix2/test/test_malware.py
@@ -3,10 +3,12 @@ import re
 
 import pytest
 import pytz
+
 import stix2
 
 from .constants import FAKE_TIME, MALWARE_ID, MALWARE_KWARGS
 
+
 EXPECTED_MALWARE = """{
     "created": "2016-05-12T08:17:27Z",
     "id": "malware--fedcba98-7654-3210-fedc-ba9876543210",
diff --git a/stix2/test/test_markings.py b/stix2/test/test_markings.py
index b3cc479..f1f07db 100644
--- a/stix2/test/test_markings.py
+++ b/stix2/test/test_markings.py
@@ -2,11 +2,13 @@ import datetime as dt
 
 import pytest
 import pytz
+
 import stix2
 from stix2.other import TLP_WHITE
 
 from .constants import MARKING_DEFINITION_ID
 
+
 EXPECTED_TLP_MARKING_DEFINITION = """{
     "created": "2017-01-20T00:00:00Z",
     "definition": {
diff --git a/stix2/test/test_observed_data.py b/stix2/test/test_observed_data.py
index 2910d3b..80a5b14 100644
--- a/stix2/test/test_observed_data.py
+++ b/stix2/test/test_observed_data.py
@@ -3,10 +3,12 @@ import re
 
 import pytest
 import pytz
+
 import stix2
 
-from .constants import OBSERVED_DATA_ID
 from ..exceptions import InvalidValueError
+from .constants import OBSERVED_DATA_ID
+
 
 EXPECTED = """{
     "created": "2016-04-06T19:58:16Z",
diff --git a/stix2/test/test_properties.py b/stix2/test/test_properties.py
index 7321a5c..d1c949c 100644
--- a/stix2/test/test_properties.py
+++ b/stix2/test/test_properties.py
@@ -4,9 +4,9 @@ from stix2.exceptions import DictionaryKeyError
 from stix2.observables import EmailMIMEComponent
 from stix2.properties import (BinaryProperty, BooleanProperty,
                               DictionaryProperty, EmbeddedObjectProperty,
-                              HashesProperty, HexProperty,
-                              IDProperty, IntegerProperty, ListProperty,
-                              Property, ReferenceProperty, StringProperty,
+                              HashesProperty, HexProperty, IDProperty,
+                              IntegerProperty, ListProperty, Property,
+                              ReferenceProperty, StringProperty,
                               TimestampProperty, TypeProperty)
 
 from .constants import FAKE_TIME
diff --git a/stix2/test/test_relationship.py b/stix2/test/test_relationship.py
index 869107d..e05c262 100644
--- a/stix2/test/test_relationship.py
+++ b/stix2/test/test_relationship.py
@@ -5,8 +5,8 @@ import pytz
 
 import stix2
 
-from .constants import FAKE_TIME, INDICATOR_ID, MALWARE_ID, RELATIONSHIP_ID
-from .constants import RELATIONSHIP_KWARGS
+from .constants import (FAKE_TIME, INDICATOR_ID, MALWARE_ID, RELATIONSHIP_ID,
+                        RELATIONSHIP_KWARGS)
 
 
 EXPECTED_RELATIONSHIP = """{
diff --git a/stix2/test/test_report.py b/stix2/test/test_report.py
index 46a0a16..cec217a 100644
--- a/stix2/test/test_report.py
+++ b/stix2/test/test_report.py
@@ -2,10 +2,12 @@ import datetime as dt
 
 import pytest
 import pytz
+
 import stix2
 
 from .constants import INDICATOR_KWARGS, REPORT_ID
 
+
 EXPECTED = """{
     "created": "2015-12-21T19:59:11Z",
     "created_by_ref": "identity--a463ffb3-1bd9-4d94-b02d-74e4f1658283",
diff --git a/stix2/test/test_threat_actor.py b/stix2/test/test_threat_actor.py
index 5844775..93e8179 100644
--- a/stix2/test/test_threat_actor.py
+++ b/stix2/test/test_threat_actor.py
@@ -2,10 +2,12 @@ import datetime as dt
 
 import pytest
 import pytz
+
 import stix2
 
 from .constants import THREAT_ACTOR_ID
 
+
 EXPECTED = """{
     "created": "2016-04-06T20:03:48Z",
     "created_by_ref": "identity--f431f809-377b-45e0-aa1c-6a4751cae5ff",
diff --git a/stix2/test/test_tool.py b/stix2/test/test_tool.py
index 3193807..d7d3bef 100644
--- a/stix2/test/test_tool.py
+++ b/stix2/test/test_tool.py
@@ -2,10 +2,12 @@ import datetime as dt
 
 import pytest
 import pytz
+
 import stix2
 
 from .constants import TOOL_ID
 
+
 EXPECTED = """{
     "created": "2016-04-06T20:03:48Z",
     "created_by_ref": "identity--f431f809-377b-45e0-aa1c-6a4751cae5ff",
diff --git a/stix2/test/test_versioning.py b/stix2/test/test_versioning.py
index 4663263..34f1c56 100644
--- a/stix2/test/test_versioning.py
+++ b/stix2/test/test_versioning.py
@@ -1,4 +1,5 @@
 import pytest
+
 import stix2
 
 
diff --git a/stix2/test/test_vulnerability.py b/stix2/test/test_vulnerability.py
index 565f077..751460c 100644
--- a/stix2/test/test_vulnerability.py
+++ b/stix2/test/test_vulnerability.py
@@ -2,10 +2,12 @@ import datetime as dt
 
 import pytest
 import pytz
+
 import stix2
 
 from .constants import VULNERABILITY_ID
 
+
 EXPECTED = """{
     "created": "2016-05-12T08:17:27Z",
     "external_references": [
diff --git a/stix2/utils.py b/stix2/utils.py
index a2493e2..6f3425f 100644
--- a/stix2/utils.py
+++ b/stix2/utils.py
@@ -3,8 +3,8 @@
 import datetime as dt
 import json
 
-from dateutil import parser
 import pytz
+from dateutil import parser
 
 # Sentinel value for fields that should be set to the current time.
 # We can't use the standard 'default' approach, since if there are multiple
diff --git a/tox.ini b/tox.ini
index 16e46e0..106db9d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py26,py27,py33,py34,py35,py36,pycodestyle
+envlist = py26,py27,py33,py34,py35,py36,pycodestyle,isort-check
 
 [testenv]
 deps =
@@ -18,11 +18,10 @@ passenv = CI TRAVIS TRAVIS_*
 [testenv:pycodestyle]
 deps =
   flake8
-  flake8-import-order
   pycodestyle
 commands =
   pycodestyle ./stix2
-  flake8 --max-line-length=160 --import-order-style='google'
+  flake8 --max-line-length=160
 
 [pycodestyle]
 ignore=
@@ -31,6 +30,10 @@ max-line-length=160
 [flake8]
 max-line-length=160
 
+[testenv:isort-check]
+deps = isort
+commands = isort -ns __init__.py -c -rc stix2 
+
 [travis]
 python =
   2.6: py26