diff --git a/src/megasniff/deflator.py b/src/megasniff/deflator.py
index 20cf150..b5c02f3 100644
--- a/src/megasniff/deflator.py
+++ b/src/megasniff/deflator.py
@@ -257,6 +257,7 @@ class SchemaDeflatorGenerator:
                     recurcive_types |= arg_rec
                 ret_unw = UnionUnwrapping(union_unwraps)
             else:
+                print(f'Unable to generate unwrapper for {schema} -- origin {origin} is not supported')
                 raise NotImplementedError
         else:
             if schema is int: