diff --git a/crates/relax-macros/src/lib.rs b/crates/relax-macros/src/lib.rs
index cab40ff..e2d2710 100644
--- a/crates/relax-macros/src/lib.rs
+++ b/crates/relax-macros/src/lib.rs
@@ -135,21 +135,15 @@ fn derive_impl(input: syn::DeriveInput) -> syn::Result<TokenStream> {
             let vis = &field.vis;
             let ty = &field.ty;
 
-            let relax_attr = field
-                .attrs
-                .iter()
-                .find(|attr| attr.path().is_ident("relax"));
-
-            if relax_attr.is_none() {
+            if field.attrs.iter().any(|attr| attr.path().is_ident("relax")) {
+                // nested
+                Ok(quote! { #vis #name: ::std::option::Option<<#ty as ::relax::Relax>::Partial> })
+            } else {
                 // not nested
                 match get_generic_ty("Option", ty) {
                     Some(ty) => Ok(quote! { #vis #name: ::std::option::Option<#ty> }),
                     None => Ok(quote! { #vis #name: ::std::option::Option<#ty> }),
                 }
-            } else {
-                // nested
-                let ty = get_ty_name_from_helper_attr(relax_attr.unwrap())?;
-                Ok(quote! { #vis #name: ::std::option::Option<#ty> })
             }
         })
         .collect::<syn::Result<Vec<_>>>()?;
@@ -169,18 +163,16 @@ fn derive_impl(input: syn::DeriveInput) -> syn::Result<TokenStream> {
     let try_from_fields = fields.iter().map(|field| -> syn::Result<TokenStream> {
         let name = field.ident.as_ref();
         let ty = &field.ty;
-        let relaxed_ty = field
+        let nested = field
             .attrs
             .iter()
-            .find(|attr| attr.path().is_ident("relax"))
-            .map(get_ty_name_from_helper_attr)
-            .transpose()?;
+            .any(|attr| attr.path().is_ident("relax"));
 
-        Ok(match (relaxed_ty, get_generic_ty("Option", ty)) {
-            (None, None) => quote! { #name: value.#name.ok_or(::relax::RequiredFieldNotSet(stringify!(#name)))? },
-            (None, Some(_)) => quote! { #name: value.#name },
-            (Some(_), None) => quote! { #name: value.#name.ok_or(::relax::RequiredFieldNotSet(stringify!(#name)))?.try_into()? },
-            (Some(_), Some(_)) => quote! { #name: value.#name.map(|val| val.try_into()).transpose().ok().flatten() },
+        Ok(match (nested, get_generic_ty("Option", ty).is_some()) {
+            (false, false) => quote! { #name: value.#name.ok_or(::relax::MissingRequiredField(stringify!(#name)))? },
+            (false, true) => quote! { #name: value.#name },
+            (true, false) => quote! { #name: value.#name.ok_or(::relax::MissingRequiredField(stringify!(#name)))?.try_into()? },
+            (true, true) => quote! { #name: value.#name.map(|val| val.try_into()).transpose().ok().flatten() },
         })
     }).collect::<syn::Result<Vec<_>>>()?;
 
@@ -204,7 +196,7 @@ fn derive_impl(input: syn::DeriveInput) -> syn::Result<TokenStream> {
         }
 
         impl #generics ::std::convert::TryFrom<#partial #generics> for #base #generics {
-            type Error = ::relax::RequiredFieldNotSet;
+            type Error = ::relax::MissingRequiredField;
 
             fn try_from(value: #partial) -> ::std::result::Result<Self, Self::Error> {
                 Ok(Self{
@@ -250,29 +242,3 @@ fn get_generic_ty<'a>(wrapper: &str, ty: &'a syn::Type) -> Option<&'a syn::Type>
         None
     }
 }
-
-fn get_ty_name_from_helper_attr(attr: &syn::Attribute) -> syn::Result<TokenTree> {
-    let tokens = match attr {
-        syn::Attribute {
-            meta: syn::Meta::List(syn::MetaList { ref tokens, .. }),
-            ..
-        } => tokens,
-        _ => {
-            return Err(syn::Error::new_spanned(
-                attr,
-                "helper attribute should be #[relax(StructName)]",
-            ))
-        }
-    };
-
-    let tokens: Vec<TokenTree> = tokens.clone().into_iter().collect();
-
-    if tokens.len() != 1 {
-        return Err(syn::Error::new_spanned(
-            attr,
-            "helper attribute should be #[relax(StructName)]",
-        ));
-    }
-
-    Ok(tokens[0].to_owned())
-}