diff --git a/src/r0/sync.rs b/src/r0/sync.rs
index 5b897fdc..7a45c35b 100644
--- a/src/r0/sync.rs
+++ b/src/r0/sync.rs
@@ -260,6 +260,7 @@ pub mod sync_events {
 
     /// A filter represented either as its full JSON definition or the ID of a saved filter.
     #[derive(Clone, Debug, Deserialize, Serialize)]
+    #[serde(untagged)]
     pub enum Filter {
         /// A complete filter definition serialized to JSON.
         FilterDefinition(FilterDefinition),