diff --git a/crates/relax-macros/src/lib.rs b/crates/relax-macros/src/lib.rs
index c2e6b82..bc22927 100644
--- a/crates/relax-macros/src/lib.rs
+++ b/crates/relax-macros/src/lib.rs
@@ -143,6 +143,11 @@ fn derive_impl(input: syn::DeriveInput) -> syn::Result<TokenStream> {
 
     let base = &input.ident;
 
+    let new_fields = fields.iter().map(|field| {
+        let name = field.ident.as_ref();
+        quote! { #name: ::std::option::Option::None }
+    });
+
     let from_fields = fields.iter().map(|field| {
         let name = field.ident.as_ref();
         let ty = &field.ty;
@@ -216,6 +221,12 @@ fn derive_impl(input: syn::DeriveInput) -> syn::Result<TokenStream> {
         impl #generics ::relax::Relaxed for #partial #generics {
             type Complete = #base #generics;
 
+            fn new() -> Self {
+                Self {
+                    #(#new_fields),*
+                }
+            }
+
             fn merge(self, optb: Self) -> Self {
                 Self {
                     #(#merge_fields),*
diff --git a/crates/relax/src/lib.rs b/crates/relax/src/lib.rs
index 5325a7c..12adb9a 100644
--- a/crates/relax/src/lib.rs
+++ b/crates/relax/src/lib.rs
@@ -9,6 +9,8 @@ pub trait Relax: TryFrom<Self::Partial, Error = RequiredFieldNotSet> {
 
 pub trait Relaxed: From<Self::Complete> {
     type Complete;
+
+    fn new() -> Self;
     fn merge(self, optb: Self) -> Self;
 }