diff --git a/crates/rpc-types-engine/src/superchain.rs b/crates/rpc-types-engine/src/superchain.rs
index 6a07ffa0..0af437a9 100644
--- a/crates/rpc-types-engine/src/superchain.rs
+++ b/crates/rpc-types-engine/src/superchain.rs
@@ -1,4 +1,7 @@
-use alloc::{format, string::String};
+use alloc::{
+    format,
+    string::{String, ToString},
+};
 use core::array::TryFromSliceError;
 
 use alloy_primitives::{B256, B64};