diff --git a/src/sliding-sync.ts b/src/sliding-sync.ts
index 28026b3a999..6c19a35fa7d 100644
--- a/src/sliding-sync.ts
+++ b/src/sliding-sync.ts
@@ -47,6 +47,8 @@ export interface MSC3575Filter {
     room_types?: string[];
     not_room_types?: string[];
     spaces?: string[];
+    tags?: string[];
+    not_tags?: string[];
 }
 
 /**