diff --git a/acme/acme/client.py b/acme/acme/client.py
index bc93ca06f..1f4ae4fad 100644
--- a/acme/acme/client.py
+++ b/acme/acme/client.py
@@ -1,7 +1,6 @@
 """ACME client API."""
 import base64
 import collections
-import cryptography
 import datetime
 from email.utils import parsedate_tz
 import heapq
@@ -17,6 +16,7 @@ import re
 import requests
 import sys
 
+from acme import crypto_util
 from acme import errors
 from acme import jws
 from acme import messages
@@ -568,11 +568,9 @@ class ClientV2(ClientBase):
         :returns: The newly created order.
         :rtype: OrderResource
         """
-        csr = cryptography.x509.load_pem_x509_csr(csr_pem,
-            cryptography.hazmat.backends.default_backend())
-        san_extension = next(ext for ext in csr.extensions
-            if ext.oid == cryptography.x509.oid.ExtensionOID.SUBJECT_ALTERNATIVE_NAME)
-        dnsNames = san_extension.value.get_values_for_type(cryptography.x509.DNSName)
+        csr = OpenSSL.crypto.load_certificate_request(OpenSSL.crypto.FILETYPE_PEM, csr_pem)
+        # pylint: disable=protected-access
+        dnsNames = crypto_util._pyopenssl_cert_or_req_all_names(csr)
 
         identifiers = []
         for name in dnsNames:
diff --git a/acme/acme/crypto_util.py b/acme/acme/crypto_util.py
index b8fba0348..a986721f0 100644
--- a/acme/acme/crypto_util.py
+++ b/acme/acme/crypto_util.py
@@ -186,6 +186,15 @@ def make_csr(private_key_pem, domains, must_staple=False):
     return OpenSSL.crypto.dump_certificate_request(
         OpenSSL.crypto.FILETYPE_PEM, csr)
 
+def _pyopenssl_cert_or_req_all_names(loaded_cert_or_req):
+    common_name = loaded_cert_or_req.get_subject().CN
+    sans = _pyopenssl_cert_or_req_san(loaded_cert_or_req)
+
+    if common_name is None:
+        return sans
+    else:
+        return [common_name] + [d for d in sans if d != common_name]
+
 def _pyopenssl_cert_or_req_san(cert_or_req):
     """Get Subject Alternative Names from certificate or CSR using pyOpenSSL.
 
diff --git a/acme/acme/crypto_util_test.py b/acme/acme/crypto_util_test.py
index 1d7f83ccf..14aaac8b5 100644
--- a/acme/acme/crypto_util_test.py
+++ b/acme/acme/crypto_util_test.py
@@ -65,6 +65,30 @@ class SSLSocketAndProbeSNITest(unittest.TestCase):
     #    self.assertRaises(errors.Error, self._probe, b'bar')
 
 
+class PyOpenSSLCertOrReqAllNamesTest(unittest.TestCase):
+    """Test for acme.crypto_util._pyopenssl_cert_or_req_all_names."""
+
+    @classmethod
+    def _call(cls, loader, name):
+        # pylint: disable=protected-access
+        from acme.crypto_util import _pyopenssl_cert_or_req_all_names
+        return _pyopenssl_cert_or_req_all_names(loader(name))
+
+    def _call_cert(self, name):
+        return self._call(test_util.load_cert, name)
+
+    def test_cert_one_san_no_common(self):
+        self.assertEqual(self._call_cert('cert-nocn.der'),
+                         ['no-common-name.badssl.com'])
+
+    def test_cert_no_sans_yes_common(self):
+        self.assertEqual(self._call_cert('cert.pem'), ['example.com'])
+
+    def test_cert_two_sans_yes_common(self):
+        self.assertEqual(self._call_cert('cert-san.pem'),
+                         ['example.com', 'www.example.com'])
+
+
 class PyOpenSSLCertOrReqSANTest(unittest.TestCase):
     """Test for acme.crypto_util._pyopenssl_cert_or_req_san."""
 
diff --git a/acme/acme/testdata/cert-nocn.der b/acme/acme/testdata/cert-nocn.der
new file mode 100644
index 000000000..59da83ccc
Binary files /dev/null and b/acme/acme/testdata/cert-nocn.der differ
diff --git a/certbot/crypto_util.py b/certbot/crypto_util.py
index 3ae16529d..8368855cd 100644
--- a/certbot/crypto_util.py
+++ b/certbot/crypto_util.py
@@ -340,14 +340,8 @@ def _get_names_from_cert_or_req(cert_or_req, load_func, typ):
 
 
 def _get_names_from_loaded_cert_or_req(loaded_cert_or_req):
-    common_name = loaded_cert_or_req.get_subject().CN
     # pylint: disable=protected-access
-    sans = acme_crypto_util._pyopenssl_cert_or_req_san(loaded_cert_or_req)
-
-    if common_name is None:
-        return sans
-    else:
-        return [common_name] + [d for d in sans if d != common_name]
+    return acme_crypto_util._pyopenssl_cert_or_req_all_names(loaded_cert_or_req)
 
 
 def get_names_from_cert(csr, typ=OpenSSL.crypto.FILETYPE_PEM):