diff --git a/src/broadcast_messages.rs b/src/broadcast_messages.rs
index 7ee8e63..4a77381 100644
--- a/src/broadcast_messages.rs
+++ b/src/broadcast_messages.rs
@@ -42,5 +42,5 @@ pub enum BroadcastMessage {
     /// Stop a client with a given client ID
     StopSyncClient(SyncClientID),
     /// Propagate a new sync event
-    SyncEvent(UserID, SyncEvent),
+    SyncEvent(UserID, Box<SyncEvent>),
 }