diff --git a/src/cryptography/x509.py b/src/cryptography/x509.py
index 978eb56..0ddff72 100644
--- a/src/cryptography/x509.py
+++ b/src/cryptography/x509.py
@@ -1752,4 +1752,22 @@
         """
         Signs the certificate using the CA's private key.
         """
+        if self._subject_name is None:
+            raise ValueError("A certificate must have a subject name")
+
+        if self._issuer_name is None:
+            raise ValueError("A certificate must have an issuer name")
+
+        if self._serial_number is None:
+            raise ValueError("A certificate must have a serial number")
+
+        if self._not_valid_before is None:
+            raise ValueError("A certificate must have a not valid before time")
+
+        if self._not_valid_after is None:
+            raise ValueError("A certificate must have a not valid after time")
+
+        if self._public_key is None:
+            raise ValueError("A certificate must have a public key")
+
         return backend.sign_x509_certificate(self, private_key, algorithm)
diff --git a/tests/test_x509.py b/tests/test_x509.py
index e31b57f..956eaf1 100644
--- a/tests/test_x509.py
+++ b/tests/test_x509.py
@@ -828,6 +828,114 @@
 
 
 class TestCertificateBuilder(object):
+    @pytest.mark.requires_backend_interface(interface=RSABackend)
+    @pytest.mark.requires_backend_interface(interface=X509Backend)
+    def test_no_subject_name(self, backend):
+        subject_private_key = RSA_KEY_2048.private_key(backend)
+        builder = x509.CertificateBuilder().serial_number(
+            777
+        ).issuer_name(x509.Name([
+            x509.NameAttribute(x509.OID_COUNTRY_NAME, u'US'),
+        ])).public_key(
+            subject_private_key.public_key()
+        ).not_valid_before(
+            datetime.datetime(2002, 1, 1, 12, 1)
+        ).not_valid_after(
+            datetime.datetime(2030, 12, 31, 8, 30)
+        )
+        with pytest.raises(ValueError):
+            builder.sign(subject_private_key, hashes.SHA256(), backend)
+
+    @pytest.mark.requires_backend_interface(interface=RSABackend)
+    @pytest.mark.requires_backend_interface(interface=X509Backend)
+    def test_no_issuer_name(self, backend):
+        subject_private_key = RSA_KEY_2048.private_key(backend)
+        builder = x509.CertificateBuilder().serial_number(
+            777
+        ).subject_name(x509.Name([
+            x509.NameAttribute(x509.OID_COUNTRY_NAME, u'US'),
+        ])).public_key(
+            subject_private_key.public_key()
+        ).not_valid_before(
+            datetime.datetime(2002, 1, 1, 12, 1)
+        ).not_valid_after(
+            datetime.datetime(2030, 12, 31, 8, 30)
+        )
+        with pytest.raises(ValueError):
+            builder.sign(subject_private_key, hashes.SHA256(), backend)
+
+    @pytest.mark.requires_backend_interface(interface=RSABackend)
+    @pytest.mark.requires_backend_interface(interface=X509Backend)
+    def test_no_public_key(self, backend):
+        subject_private_key = RSA_KEY_2048.private_key(backend)
+        builder = x509.CertificateBuilder().serial_number(
+            777
+        ).issuer_name(x509.Name([
+            x509.NameAttribute(x509.OID_COUNTRY_NAME, u'US'),
+        ])).subject_name(x509.Name([
+            x509.NameAttribute(x509.OID_COUNTRY_NAME, u'US'),
+        ])).not_valid_before(
+            datetime.datetime(2002, 1, 1, 12, 1)
+        ).not_valid_after(
+            datetime.datetime(2030, 12, 31, 8, 30)
+        )
+        with pytest.raises(ValueError):
+            builder.sign(subject_private_key, hashes.SHA256(), backend)
+
+    @pytest.mark.requires_backend_interface(interface=RSABackend)
+    @pytest.mark.requires_backend_interface(interface=X509Backend)
+    def test_no_not_valid_before(self, backend):
+        subject_private_key = RSA_KEY_2048.private_key(backend)
+        builder = x509.CertificateBuilder().serial_number(
+            777
+        ).issuer_name(x509.Name([
+            x509.NameAttribute(x509.OID_COUNTRY_NAME, u'US'),
+        ])).subject_name(x509.Name([
+            x509.NameAttribute(x509.OID_COUNTRY_NAME, u'US'),
+        ])).public_key(
+            subject_private_key.public_key()
+        ).not_valid_after(
+            datetime.datetime(2030, 12, 31, 8, 30)
+        )
+        with pytest.raises(ValueError):
+            builder.sign(subject_private_key, hashes.SHA256(), backend)
+
+    @pytest.mark.requires_backend_interface(interface=RSABackend)
+    @pytest.mark.requires_backend_interface(interface=X509Backend)
+    def test_no_not_valid_after(self, backend):
+        subject_private_key = RSA_KEY_2048.private_key(backend)
+        builder = x509.CertificateBuilder().serial_number(
+            777
+        ).issuer_name(x509.Name([
+            x509.NameAttribute(x509.OID_COUNTRY_NAME, u'US'),
+        ])).subject_name(x509.Name([
+            x509.NameAttribute(x509.OID_COUNTRY_NAME, u'US'),
+        ])).public_key(
+            subject_private_key.public_key()
+        ).not_valid_before(
+            datetime.datetime(2002, 1, 1, 12, 1)
+        )
+        with pytest.raises(ValueError):
+            builder.sign(subject_private_key, hashes.SHA256(), backend)
+
+    @pytest.mark.requires_backend_interface(interface=RSABackend)
+    @pytest.mark.requires_backend_interface(interface=X509Backend)
+    def test_no_serial_number(self, backend):
+        subject_private_key = RSA_KEY_2048.private_key(backend)
+        builder = x509.CertificateBuilder().issuer_name(x509.Name([
+            x509.NameAttribute(x509.OID_COUNTRY_NAME, u'US'),
+        ])).subject_name(x509.Name([
+            x509.NameAttribute(x509.OID_COUNTRY_NAME, u'US'),
+        ])).public_key(
+            subject_private_key.public_key()
+        ).not_valid_before(
+            datetime.datetime(2002, 1, 1, 12, 1)
+        ).not_valid_after(
+            datetime.datetime(2030, 12, 31, 8, 30)
+        )
+        with pytest.raises(ValueError):
+            builder.sign(subject_private_key, hashes.SHA256(), backend)
+
     def test_issuer_name_must_be_a_name_type(self):
         builder = x509.CertificateBuilder()
 
@@ -967,6 +1075,19 @@
     def test_sign_with_unsupported_hash(self, backend):
         private_key = RSA_KEY_2048.private_key(backend)
         builder = x509.CertificateBuilder()
+        builder = builder.subject_name(
+            x509.Name([x509.NameAttribute(x509.OID_COUNTRY_NAME, u'US')])
+        ).issuer_name(
+            x509.Name([x509.NameAttribute(x509.OID_COUNTRY_NAME, u'US')])
+        ).serial_number(
+            1
+        ).public_key(
+            private_key.public_key()
+        ).not_valid_before(
+            datetime.datetime(2002, 1, 1, 12, 1)
+        ).not_valid_after(
+            datetime.datetime(2032, 1, 1, 12, 1)
+        )
 
         with pytest.raises(TypeError):
             builder.sign(private_key, object(), backend)