diff --git a/crates/xml/derive/src/field.rs b/crates/xml/derive/src/field.rs
index 3196805..bf13cbf 100644
--- a/crates/xml/derive/src/field.rs
+++ b/crates/xml/derive/src/field.rs
@@ -157,7 +157,8 @@ impl Field {
             (false, true, false) => quote! { builder.#builder_field_ident },
             (false, false, true) => quote! { builder.#builder_field_ident },
             (false, false, false) => {
-                quote! { builder.#builder_field_ident.expect("todo: handle missing field") }
+                let field_ident = self.field_ident().into_token_stream().to_string();
+                quote! { builder.#builder_field_ident.ok_or(::rustical_xml::XmlDeError::MissingField(#field_ident))? }
             }
         };
         quote! { #target_field_index: #builder_value }