diff --git a/MV64e.MTB/Mtb.cs b/MV64e.MTB/Mtb.cs
index 11d9851..6a302c4 100644
--- a/MV64e.MTB/Mtb.cs
+++ b/MV64e.MTB/Mtb.cs
@@ -1644,6 +1644,7 @@ internal static class Converter
         {
             MetadataPropertyHandling = MetadataPropertyHandling.Ignore,
             DateParseHandling = DateParseHandling.None,
+            MissingMemberHandling = MissingMemberHandling.Error,
             Converters =
             {
                 PatientTypeConverter.Singleton,