diff --git a/src/core/lib/transport/call_spine.h b/src/core/lib/transport/call_spine.h
index 92f05fc43c8..7b352f228eb 100644
--- a/src/core/lib/transport/call_spine.h
+++ b/src/core/lib/transport/call_spine.h
@@ -179,7 +179,7 @@ class CallSpine final : public CallSpineInterface, public Party {
   friend class Arena;
   CallSpine(grpc_event_engine::experimental::EventEngine* event_engine,
             Arena* arena)
-      : Party(1), event_engine_(event_engine) {}
+      : Party(1), arena_(arena), event_engine_(event_engine) {}
 
   class ScopedContext : public ScopedActivity,
                         public promise_detail::Context<Arena> {