2 files changed, 4 insertions, 4 deletions
diff --git a/src/cryptography/hazmat/backends/openssl/x509.py b/src/cryptography/hazmat/backends/openssl/x509.py
index 4126a397..a348630f 100644
--- a/src/cryptography/hazmat/backends/openssl/x509.py
+++ b/src/cryptography/hazmat/backends/openssl/x509.py
@@ -83,12 +83,12 @@ class _X509Certificate(object):
         return self._backend._evp_pkey_to_public_key(pkey)
 
     @property
-    def not_before(self):
+    def not_valid_before(self):
         asn1_time = self._backend._lib.X509_get_notBefore(self._x509)
         return self._parse_asn1_time(asn1_time)
 
     @property
-    def not_after(self):
+    def not_valid_after(self):
         asn1_time = self._backend._lib.X509_get_notAfter(self._x509)
         return self._parse_asn1_time(asn1_time)
 
diff --git a/src/cryptography/hazmat/primitives/interfaces.py b/src/cryptography/hazmat/primitives/interfaces.py
index 18a62601..76616e1f 100644
--- a/src/cryptography/hazmat/primitives/interfaces.py
+++ b/src/cryptography/hazmat/primitives/interfaces.py
@@ -517,13 +517,13 @@ class X509Certificate(object):
         """
 
     @abc.abstractproperty
-    def not_before(self):
+    def not_valid_before(self):
         """
         Not before time (represented as UTC datetime)
         """
 
     @abc.abstractproperty
-    def not_after(self):
+    def not_valid_after(self):
         """
         Not after time (represented as UTC datetime)
         """