diff --git a/crates/primitives/src/serde_helper/mod.rs b/crates/primitives/src/serde_helper/mod.rs
index 6c5b699b318..800df016266 100644
--- a/crates/primitives/src/serde_helper/mod.rs
+++ b/crates/primitives/src/serde_helper/mod.rs
@@ -33,7 +33,6 @@ pub mod u64_hex {
 }
 
 /// serde functions for handling `Option<u64>` as [U64](crate::U64)
-#[cfg(feature = "optimism")]
 pub mod option_u64_hex {
     use crate::U64;
     use serde::{Deserialize, Deserializer};