Fix test failures
diff --git a/tests/hazmat/backends/test_commoncrypto.py b/tests/hazmat/backends/test_commoncrypto.py
index e2c6f4a..28d1a6c 100644
--- a/tests/hazmat/backends/test_commoncrypto.py
+++ b/tests/hazmat/backends/test_commoncrypto.py
@@ -17,7 +17,7 @@
 
 from cryptography import utils
 from cryptography.exceptions import InternalError, _Reasons
-from cryptography.hazmat.bindings.commoncrypto.binding import Binding
+from cryptography.hazmat.backends import _available_backends
 from cryptography.hazmat.primitives import interfaces
 from cryptography.hazmat.primitives.ciphers.algorithms import AES
 from cryptography.hazmat.primitives.ciphers.base import Cipher
@@ -32,7 +32,8 @@
     block_size = 128
 
 
-@pytest.mark.skipif(not Binding.is_available(),
+@pytest.mark.skipif("commoncrypto" not in
+                    [i.name for i in _available_backends()],
                     reason="CommonCrypto not available")
 class TestCommonCrypto(object):
     def test_supports_cipher(self):
diff --git a/tests/hazmat/bindings/test_commoncrypto.py b/tests/hazmat/bindings/test_commoncrypto.py
index 0332674..71c832e 100644
--- a/tests/hazmat/bindings/test_commoncrypto.py
+++ b/tests/hazmat/bindings/test_commoncrypto.py
@@ -15,10 +15,12 @@
 
 import pytest
 
+from cryptography.hazmat.backends import _available_backends
 from cryptography.hazmat.bindings.commoncrypto.binding import Binding
 
 
-@pytest.mark.skipif(not Binding.is_available(),
+@pytest.mark.skipif("commoncrypto" not in
+                    [i.name for i in _available_backends()],
                     reason="CommonCrypto not available")
 class TestCommonCrypto(object):
     def test_binding_loads(self):
diff --git a/tests/hazmat/bindings/test_openssl.py b/tests/hazmat/bindings/test_openssl.py
index d22c4fd..ca6e9ab 100644
--- a/tests/hazmat/bindings/test_openssl.py
+++ b/tests/hazmat/bindings/test_openssl.py
@@ -27,9 +27,6 @@
         assert binding.lib
         assert binding.ffi
 
-    def test_is_available(self):
-        assert Binding.is_available() is True
-
     def test_crypto_lock_init(self):
         b = Binding()
         b.init_static_locks()