Skip tests when the EC curve is unsupported
diff --git a/tests/test_x509.py b/tests/test_x509.py
index 5d6f174..fb7f17d 100644
--- a/tests/test_x509.py
+++ b/tests/test_x509.py
@@ -768,6 +768,7 @@
         if backend._lib.OPENSSL_VERSION_NUMBER < 0x10001000:
             pytest.skip("Requires a newer OpenSSL. Must be >= 1.0.1")
 
+        _skip_curve_unsupported(backend, ec.SECT283K1())
         private_key = ec.generate_private_key(ec.SECT283K1(), backend)
 
         request = x509.CertificateSigningRequestBuilder().subject_name(