diff --git a/macro/src/expand.rs b/macro/src/expand.rs
index 9f16e5e..43f152b 100644
--- a/macro/src/expand.rs
+++ b/macro/src/expand.rs
@@ -68,13 +68,17 @@
         let explicit_impl = types.explicit_impls.get(ty);
         if let Type::RustBox(ty) = ty {
             if let Type::Ident(ident) = &ty.inner {
-                if Atom::from(&ident.rust).is_none() {
+                if Atom::from(&ident.rust).is_none()
+                    && (explicit_impl.is_some() || !types.aliases.contains_key(&ident.rust))
+                {
                     hidden.extend(expand_rust_box(ident, types));
                 }
             }
         } else if let Type::RustVec(ty) = ty {
             if let Type::Ident(ident) = &ty.inner {
-                if Atom::from(&ident.rust).is_none() {
+                if Atom::from(&ident.rust).is_none()
+                    && (explicit_impl.is_some() || !types.aliases.contains_key(&ident.rust))
+                {
                     hidden.extend(expand_rust_vec(ident, types));
                 }
             }