diff --git a/tests/test_x509.py b/tests/test_x509.py
index eac8a30..0a120eb 100644
--- a/tests/test_x509.py
+++ b/tests/test_x509.py
@@ -94,3 +94,12 @@
         )
         with pytest.raises(InvalidX509Version):
             cert.version
+
+    def test_version_1_cert(self, backend):
+        cert = load_vectors_from_file(
+            os.path.join("x509", "v1_cert.pem"),
+            lambda pemfile: x509.load_pem_x509_certificate(
+                pemfile.read(), backend
+            )
+        )
+        assert cert.version == x509.X509Version.v1