diff --git a/serde_derive_internals/src/attr.rs b/serde_derive_internals/src/attr.rs
index b62e4748..04294df3 100644
--- a/serde_derive_internals/src/attr.rs
+++ b/serde_derive_internals/src/attr.rs
@@ -757,7 +757,6 @@ pub struct Field {
     de_bound: Option<Vec<syn::WherePredicate>>,
     borrowed_lifetimes: BTreeSet<syn::Lifetime>,
     getter: Option<syn::ExprPath>,
-    collection_field: bool,
     flatten: bool,
 }