diff --git a/cryptography/hazmat/backends/openssl/backend.py b/cryptography/hazmat/backends/openssl/backend.py
index 1173113..0692492 100644
--- a/cryptography/hazmat/backends/openssl/backend.py
+++ b/cryptography/hazmat/backends/openssl/backend.py
@@ -25,7 +25,7 @@
     UnsupportedAlgorithm, _Reasons
 )
 from cryptography.hazmat.backends.interfaces import (
-    CipherBackend, CMACBackend, DSABackend, HMACBackend, HashBackend,
+    CMACBackend, CipherBackend, DSABackend, HMACBackend, HashBackend,
     PBKDF2HMACBackend, RSABackend
 )
 from cryptography.hazmat.bindings.openssl.binding import Binding
diff --git a/tests/conftest.py b/tests/conftest.py
index 6ba8ae0..d55e6cf 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -17,7 +17,7 @@
 
 from cryptography.hazmat.backends import _available_backends
 from cryptography.hazmat.backends.interfaces import (
-    CipherBackend, CMACBackend, DSABackend, HMACBackend, HashBackend,
+    CMACBackend, CipherBackend, DSABackend, HMACBackend, HashBackend,
     PBKDF2HMACBackend, RSABackend
 )
 from .utils import check_backend_support, check_for_iface, select_backends
diff --git a/tests/hazmat/primitives/test_cmac.py b/tests/hazmat/primitives/test_cmac.py
index dd7f9df..2556811 100644
--- a/tests/hazmat/primitives/test_cmac.py
+++ b/tests/hazmat/primitives/test_cmac.py
@@ -32,7 +32,7 @@
 from cryptography.hazmat.primitives.cmac import CMAC
 
 from tests.utils import (
-    load_vectors_from_file, load_nist_vectors, raises_unsupported_algorithm
+    load_nist_vectors, load_vectors_from_file, raises_unsupported_algorithm
 )
 
 vectors_aes128 = load_vectors_from_file(