diff --git a/src/protocol/mod.rs b/src/protocol/mod.rs
index 8eaf5e1398e1462da4be7eace773cb7c61443368..948853abb2d906743f90a5f803cb25a5a6a4af03 100644
--- a/src/protocol/mod.rs
+++ b/src/protocol/mod.rs
@@ -1,3 +1,4 @@
+mod arena;
 mod ast;
 mod eval;
 pub mod inputsource;
@@ -95,7 +96,7 @@ impl ProtocolDescription for ProtocolDescriptionImpl {
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, serde::Serialize)]
 pub struct ComponentStateImpl {
     prompt: Prompt,
 }