diff --git a/tests/test_x509_ext.py b/tests/test_x509_ext.py
index 2c5438a..a05dc2a 100644
--- a/tests/test_x509_ext.py
+++ b/tests/test_x509_ext.py
@@ -832,6 +832,16 @@
         extensions = cert.extensions
         assert len(extensions) == 0
 
+    def test_one_extension_get_for_class(self, backend):
+        cert = _load_cert(
+            os.path.join("x509", "custom", "basic_constraints_not_critical.pem"),
+            x509.load_pem_x509_certificate,
+            backend
+        )
+        ext = cert.extensions.get_extension_for_class(x509.BasicConstraints)
+        assert ext is not None
+
+        assert isinstance(ext.value, x509.BasicConstraints)
 
 @pytest.mark.requires_backend_interface(interface=RSABackend)
 @pytest.mark.requires_backend_interface(interface=X509Backend)