diff --git a/tests/conftest.py b/tests/conftest.py
index 36183f4..8e89af5 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -17,10 +17,10 @@
 
 from cryptography.hazmat.backends import _available_backends
 from cryptography.hazmat.backends.interfaces import (
-    HMACBackend, CipherBackend, HashBackend, PBKDF2HMACBackend, RSABackend
+    CipherBackend, HMACBackend, HashBackend, PBKDF2HMACBackend, RSABackend
 )
 
-from .utils import check_for_iface, check_backend_support, select_backends
+from .utils import check_backend_support, check_for_iface, select_backends
 
 
 def pytest_generate_tests(metafunc):
diff --git a/tests/hazmat/backends/test_commoncrypto.py b/tests/hazmat/backends/test_commoncrypto.py
index 1062b2b..72ed61c 100644
--- a/tests/hazmat/backends/test_commoncrypto.py
+++ b/tests/hazmat/backends/test_commoncrypto.py
@@ -16,7 +16,7 @@
 import pytest
 
 from cryptography import utils
-from cryptography.exceptions import UnsupportedCipher, InternalError
+from cryptography.exceptions import InternalError, UnsupportedCipher
 from cryptography.hazmat.bindings.commoncrypto.binding import Binding
 from cryptography.hazmat.primitives import interfaces
 from cryptography.hazmat.primitives.ciphers.algorithms import AES
diff --git a/tests/hazmat/backends/test_multibackend.py b/tests/hazmat/backends/test_multibackend.py
index 31fb0a2..c5c0d82 100644
--- a/tests/hazmat/backends/test_multibackend.py
+++ b/tests/hazmat/backends/test_multibackend.py
@@ -20,7 +20,7 @@
     UnsupportedAlgorithm, UnsupportedCipher, UnsupportedHash
 )
 from cryptography.hazmat.backends.interfaces import (
-    CipherBackend, HashBackend, HMACBackend, PBKDF2HMACBackend, RSABackend
+    CipherBackend, HMACBackend, HashBackend, PBKDF2HMACBackend, RSABackend
 )
 from cryptography.hazmat.backends.multibackend import MultiBackend
 from cryptography.hazmat.primitives import hashes, hmac
diff --git a/tests/hazmat/backends/test_openssl.py b/tests/hazmat/backends/test_openssl.py
index c5d0a01..501ee0f 100644
--- a/tests/hazmat/backends/test_openssl.py
+++ b/tests/hazmat/backends/test_openssl.py
@@ -17,11 +17,11 @@
 
 from cryptography import utils
 from cryptography.exceptions import (
-    UnsupportedCipher, UnsupportedHash, InternalError
+    InternalError, UnsupportedCipher, UnsupportedHash
 )
-from cryptography.hazmat.backends.openssl.backend import backend, Backend
-from cryptography.hazmat.primitives import interfaces, hashes
-from cryptography.hazmat.primitives.asymmetric import rsa, padding
+from cryptography.hazmat.backends.openssl.backend import Backend, backend
+from cryptography.hazmat.primitives import hashes, interfaces
+from cryptography.hazmat.primitives.asymmetric import padding, rsa
 from cryptography.hazmat.primitives.ciphers import Cipher
 from cryptography.hazmat.primitives.ciphers.algorithms import AES
 from cryptography.hazmat.primitives.ciphers.modes import CBC
diff --git a/tests/hazmat/primitives/test_aes.py b/tests/hazmat/primitives/test_aes.py
index ad3626a..03be268 100644
--- a/tests/hazmat/primitives/test_aes.py
+++ b/tests/hazmat/primitives/test_aes.py
@@ -20,7 +20,7 @@
 
 from cryptography.hazmat.primitives.ciphers import algorithms, modes
 
-from .utils import generate_encrypt_test, generate_aead_test
+from .utils import generate_aead_test, generate_encrypt_test
 from ...utils import load_nist_vectors
 
 
diff --git a/tests/hazmat/primitives/test_block.py b/tests/hazmat/primitives/test_block.py
index 8ff00fd..f2dab6c 100644
--- a/tests/hazmat/primitives/test_block.py
+++ b/tests/hazmat/primitives/test_block.py
@@ -18,7 +18,7 @@
 import pytest
 
 from cryptography import utils
-from cryptography.exceptions import UnsupportedCipher, AlreadyFinalized
+from cryptography.exceptions import AlreadyFinalized, UnsupportedCipher
 from cryptography.hazmat.primitives import interfaces
 from cryptography.hazmat.primitives.ciphers import (
     Cipher, algorithms, modes
diff --git a/tests/hazmat/primitives/test_ciphers.py b/tests/hazmat/primitives/test_ciphers.py
index bd9625e..1bea0bd 100644
--- a/tests/hazmat/primitives/test_ciphers.py
+++ b/tests/hazmat/primitives/test_ciphers.py
@@ -20,7 +20,7 @@
 from cryptography.exceptions import UnsupportedInterface
 from cryptography.hazmat.primitives import ciphers
 from cryptography.hazmat.primitives.ciphers.algorithms import (
-    AES, Camellia, TripleDES, Blowfish, ARC4, CAST5, IDEA
+    AES, ARC4, Blowfish, CAST5, Camellia, IDEA, TripleDES
 )
 from cryptography.hazmat.primitives.ciphers.modes import ECB
 
diff --git a/tests/hazmat/primitives/test_hkdf.py b/tests/hazmat/primitives/test_hkdf.py
index 963fb69..989709c 100644
--- a/tests/hazmat/primitives/test_hkdf.py
+++ b/tests/hazmat/primitives/test_hkdf.py
@@ -13,9 +13,8 @@
 
 from __future__ import absolute_import, division, print_function
 
-import six
-
 import pytest
+import six
 
 from cryptography.exceptions import (
     AlreadyFinalized, InvalidKey, UnsupportedInterface
diff --git a/tests/hazmat/primitives/test_hmac.py b/tests/hazmat/primitives/test_hmac.py
index 3589e6a..1065359 100644
--- a/tests/hazmat/primitives/test_hmac.py
+++ b/tests/hazmat/primitives/test_hmac.py
@@ -21,7 +21,7 @@
 
 from cryptography import utils
 from cryptography.exceptions import (
-    AlreadyFinalized, UnsupportedHash, InvalidSignature, UnsupportedInterface
+    AlreadyFinalized, InvalidSignature, UnsupportedHash, UnsupportedInterface
 )
 from cryptography.hazmat.backends.interfaces import HMACBackend
 from cryptography.hazmat.primitives import hashes, hmac, interfaces
diff --git a/tests/hazmat/primitives/test_pbkdf2hmac.py b/tests/hazmat/primitives/test_pbkdf2hmac.py
index bf1e7f1..585693e 100644
--- a/tests/hazmat/primitives/test_pbkdf2hmac.py
+++ b/tests/hazmat/primitives/test_pbkdf2hmac.py
@@ -18,11 +18,11 @@
 
 from cryptography import utils
 from cryptography.exceptions import (
-    InvalidKey, UnsupportedHash, AlreadyFinalized, UnsupportedInterface
+    AlreadyFinalized, InvalidKey, UnsupportedHash, UnsupportedInterface
 )
+from cryptography.hazmat.backends import default_backend
 from cryptography.hazmat.primitives import hashes, interfaces
 from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
-from cryptography.hazmat.backends import default_backend
 
 
 @utils.register_interface(interfaces.HashAlgorithm)
diff --git a/tests/hazmat/primitives/test_rsa.py b/tests/hazmat/primitives/test_rsa.py
index 955e69c..67b5b2e 100644
--- a/tests/hazmat/primitives/test_rsa.py
+++ b/tests/hazmat/primitives/test_rsa.py
@@ -25,11 +25,11 @@
     UnsupportedAlgorithm, UnsupportedInterface
 )
 from cryptography.hazmat.primitives import hashes, interfaces
-from cryptography.hazmat.primitives.asymmetric import rsa, padding
+from cryptography.hazmat.primitives.asymmetric import padding, rsa
 
 from .utils import generate_rsa_pss_test
 from ...utils import (
-    load_pkcs1_vectors, load_vectors_from_file, load_rsa_nist_vectors
+    load_pkcs1_vectors, load_rsa_nist_vectors, load_vectors_from_file
 )
 
 
diff --git a/tests/hazmat/primitives/twofactor/test_hotp.py b/tests/hazmat/primitives/twofactor/test_hotp.py
index 548c626..7692a08 100644
--- a/tests/hazmat/primitives/twofactor/test_hotp.py
+++ b/tests/hazmat/primitives/twofactor/test_hotp.py
@@ -18,10 +18,10 @@
 import pytest
 
 from cryptography.exceptions import InvalidToken, UnsupportedInterface
-from cryptography.hazmat.primitives.twofactor.hotp import HOTP
 from cryptography.hazmat.primitives import hashes
-from tests.utils import load_vectors_from_file, load_nist_vectors
 from cryptography.hazmat.primitives.hashes import MD5, SHA1
+from cryptography.hazmat.primitives.twofactor.hotp import HOTP
+from tests.utils import load_nist_vectors, load_vectors_from_file
 
 vectors = load_vectors_from_file(
     "twofactor/rfc-4226.txt", load_nist_vectors)
diff --git a/tests/hazmat/primitives/twofactor/test_totp.py b/tests/hazmat/primitives/twofactor/test_totp.py
index 294c19a..0b10c96 100644
--- a/tests/hazmat/primitives/twofactor/test_totp.py
+++ b/tests/hazmat/primitives/twofactor/test_totp.py
@@ -18,7 +18,7 @@
 from cryptography.exceptions import InvalidToken, UnsupportedInterface
 from cryptography.hazmat.primitives import hashes
 from cryptography.hazmat.primitives.twofactor.totp import TOTP
-from tests.utils import load_vectors_from_file, load_nist_vectors
+from tests.utils import load_nist_vectors, load_vectors_from_file
 
 vectors = load_vectors_from_file(
     "twofactor/rfc-6238.txt", load_nist_vectors)
diff --git a/tests/hazmat/primitives/utils.py b/tests/hazmat/primitives/utils.py
index 3149102..a29ef70 100644
--- a/tests/hazmat/primitives/utils.py
+++ b/tests/hazmat/primitives/utils.py
@@ -14,21 +14,19 @@
 from __future__ import absolute_import, division, print_function
 
 import binascii
-import os
-
 import itertools
+import os
 
 import pytest
 
+from cryptography.exceptions import (
+    AlreadyFinalized, AlreadyUpdated, InvalidTag, NotYetFinalized
+)
 from cryptography.hazmat.primitives import hashes, hmac
-from cryptography.hazmat.primitives.asymmetric import rsa, padding
-from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
+from cryptography.hazmat.primitives.asymmetric import padding, rsa
 from cryptography.hazmat.primitives.ciphers import Cipher
 from cryptography.hazmat.primitives.kdf.hkdf import HKDF
-
-from cryptography.exceptions import (
-    AlreadyFinalized, NotYetFinalized, AlreadyUpdated, InvalidTag,
-)
+from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
 
 from ...utils import load_vectors_from_file
 
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 1003d61..e5ab4cf 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -21,10 +21,10 @@
 import pytest
 
 from .utils import (
-    load_nist_vectors, load_vectors_from_file, load_cryptrec_vectors,
-    load_hash_vectors, check_for_iface, check_backend_support,
-    select_backends, load_pkcs1_vectors, load_rsa_nist_vectors,
-    load_fips_dsa_key_pair_vectors
+    check_backend_support, check_for_iface, load_cryptrec_vectors,
+    load_fips_dsa_key_pair_vectors, load_hash_vectors, load_nist_vectors,
+    load_pkcs1_vectors, load_rsa_nist_vectors, load_vectors_from_file,
+    select_backends
 )
 
 
diff --git a/tests/utils.py b/tests/utils.py
index 4d6882c..81a86df 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -16,8 +16,8 @@
 import collections
 import os
 
-import six
 import pytest
+import six
 
 
 HashVector = collections.namedtuple("HashVector", ["message", "digest"])