diff --git a/docs/x509/reference.rst b/docs/x509/reference.rst
index e4ea252..5a80984 100644
--- a/docs/x509/reference.rst
+++ b/docs/x509/reference.rst
@@ -393,13 +393,6 @@
 
 .. class:: CertificateBuilder
 
-    .. method:: version(version)
-
-        Sets the X.509 version that will be used in the certificate.
-
-        :param version: The :class:`~cryptography.x509.Version` that will be
-            used by the certificate.
-
     .. method:: issuer_name(name)
 
         Sets the issuer's distinguished name.
diff --git a/src/cryptography/x509.py b/src/cryptography/x509.py
index 6f7aeee..4b13fce 100644
--- a/src/cryptography/x509.py
+++ b/src/cryptography/x509.py
@@ -1605,7 +1605,7 @@
         """
         Creates an empty X.509 certificate (version 1).
         """
-        self._version = version
+        self._version = Version.v3
         self._issuer_name = issuer_name
         self._subject_name = subject_name
         self._public_key = public_key
@@ -1614,20 +1614,6 @@
         self._not_valid_after = not_valid_after
         self._extensions = extensions
 
-    def version(self, version):
-        """
-        Sets the X.509 version required by decoders.
-        """
-        if not isinstance(version, Version):
-            raise TypeError('Expecting x509.Version object.')
-        if self._version is not None:
-            raise ValueError('The version may only be set once.')
-        return CertificateBuilder(
-            version, self._issuer_name, self._subject_name, self._public_key,
-            self._serial_number, self._not_valid_before,
-            self._not_valid_after, self._extensions
-        )
-
     def issuer_name(self, name):
         """
         Sets the CA's distinguished name.
@@ -1744,7 +1730,4 @@
         """
         Signs the certificate using the CA's private key.
         """
-        builder = self
-        if self._version is None:
-            builder = self.version(Version.v3)
-        return backend.sign_x509_certificate(builder, private_key, algorithm)
+        return backend.sign_x509_certificate(self, private_key, algorithm)
diff --git a/tests/hazmat/backends/test_openssl.py b/tests/hazmat/backends/test_openssl.py
index 5505c63..daa3787 100644
--- a/tests/hazmat/backends/test_openssl.py
+++ b/tests/hazmat/backends/test_openssl.py
@@ -489,9 +489,7 @@
 
     def test_checks_for_unsupported_extensions(self):
         private_key = RSA_KEY_2048.private_key(backend)
-        builder = x509.CertificateBuilder().version(
-            x509.Version.v3
-        ).subject_name(x509.Name([
+        builder = x509.CertificateBuilder().subject_name(x509.Name([
             x509.NameAttribute(x509.OID_COUNTRY_NAME, u'US'),
             x509.NameAttribute(x509.OID_STATE_OR_PROVINCE_NAME, u'Texas'),
             x509.NameAttribute(x509.OID_LOCALITY_NAME, u'Austin'),
diff --git a/tests/test_x509.py b/tests/test_x509.py
index c4a423a..e052b4d 100644
--- a/tests/test_x509.py
+++ b/tests/test_x509.py
@@ -782,9 +782,7 @@
         not_valid_before = datetime.datetime(2002, 1, 1, 12, 1)
         not_valid_after = datetime.datetime(2030, 12, 31, 8, 30)
 
-        builder = x509.CertificateBuilder().version(
-            x509.Version.v3
-        ).serial_number(
+        builder = x509.CertificateBuilder().serial_number(
             777
         ).issuer_name(x509.Name([
             x509.NameAttribute(x509.OID_COUNTRY_NAME, u'US'),
@@ -824,20 +822,6 @@
 
 
 class TestCertificateBuilder(object):
-    def test_version_must_be_a_version_type(self):
-        builder = x509.CertificateBuilder()
-
-        with pytest.raises(TypeError):
-            builder.version("v1")
-
-    def test_version_may_only_be_set_once(self):
-        builder = x509.CertificateBuilder().version(
-            x509.Version.v3
-        )
-
-        with pytest.raises(ValueError):
-            builder.version(x509.Version.v1)
-
     def test_issuer_name_must_be_a_name_type(self):
         builder = x509.CertificateBuilder()