diff --git a/src/protocol/arena.rs b/src/protocol/arena.rs
index b26df73d73b1cb9e3cac8f6fd76bf93297753a69..e55efe6a0da9a3f0b48378dedb3f230847a216a1 100644
--- a/src/protocol/arena.rs
+++ b/src/protocol/arena.rs
@@ -24,6 +24,7 @@ impl<T> Hash for Id<T> {
     }
 }
 
+#[derive(Debug, serde::Serialize, serde::Deserialize)]
 pub struct Arena<T> {
     store: Vec<T>,
 }