diff --git a/tests/conftest.py b/tests/conftest.py
index af14638..b7981c9 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -18,7 +18,8 @@
 from cryptography.hazmat.backends import _available_backends
 from cryptography.hazmat.backends.interfaces import (
     CMACBackend, CipherBackend, DSABackend, EllipticCurveBackend, HMACBackend,
-    HashBackend, PBKDF2HMACBackend, PKCS8SerializationBackend, RSABackend,
+    HashBackend, PBKDF2HMACBackend, PEMSerializationBackend,
+    PKCS8SerializationBackend, RSABackend,
     TraditionalOpenSSLSerializationBackend
 )
 from .utils import check_backend_support, check_for_iface, select_backends
@@ -48,6 +49,7 @@
     )
     check_for_iface("pkcs8_serialization", PKCS8SerializationBackend, item)
     check_for_iface("elliptic", EllipticCurveBackend, item)
+    check_for_iface("pem_serialization", PEMSerializationBackend, item)
     check_backend_support(item)