diff --git a/syntax/mod.rs b/syntax/mod.rs
index 45a4aa5..e61e384 100644
--- a/syntax/mod.rs
+++ b/syntax/mod.rs
@@ -30,7 +30,7 @@
 use proc_macro2::{Ident, Span};
 use syn::punctuated::Punctuated;
 use syn::token::{Brace, Bracket, Paren};
-use syn::{Expr, Generics, Lifetime, Token, Type as RustType};
+use syn::{Expr, Generics, Lifetime, LitInt, Token, Type as RustType};
 
 pub use self::atom::Atom;
 pub use self::derive::Derive;
@@ -196,6 +196,7 @@
     pub inner: Type,
     pub semi_token: Token![;],
     pub len: usize,
+    pub len_token: LitInt,
 }
 
 #[derive(Copy, Clone, PartialEq)]