diff --git a/transient/configuration.py b/transient/configuration.py
index e445374..6be2af8 100644
--- a/transient/configuration.py
+++ b/transient/configuration.py
@@ -108,9 +108,9 @@ def arg_to_field(arg: argparse.Action) -> fields.Field:
 
         # If this is an append action, we really want a list of these fields
         if isinstance(arg, argparse._AppendAction) or arg.nargs in ("*", "+"):
-            return fields.List(field, missing=arg.default, allow_none=True)
+            return fields.List(field, load_default=arg.default, allow_none=True)
 
-        return cast(fields.Field, field(missing=arg.default, allow_none=True))
+        return cast(fields.Field, field(load_default=arg.default, allow_none=True))
 
     class_name = "".join([word.capitalize() for word in parser.prog.split()]) + "Schema"
     return cast(