diff --git a/cassandra/cqltypes.py b/cassandra/cqltypes.py
index 7946a63af8..8167b3b894 100644
--- a/cassandra/cqltypes.py
+++ b/cassandra/cqltypes.py
@@ -1026,7 +1026,9 @@ def serialize_safe(cls, val, protocol_version):
             try:
                 item = val[i]
             except TypeError:
-                item = getattr(val, fieldname)
+                item = getattr(val, fieldname, None)
+                if item is None and not hasattr(val, fieldname):
+                    log.warning(f"field {fieldname} is part of the UDT {cls.typename} but is not present in the value {val}")
 
             if item is not None:
                 packed_item = subtype.to_binary(item, proto_version)