diff --git a/src/indexing/EventIndex.ts b/src/indexing/EventIndex.ts
index 97688d725a..fbc731e9a9 100644
--- a/src/indexing/EventIndex.ts
+++ b/src/indexing/EventIndex.ts
@@ -309,8 +309,7 @@ export default class EventIndex extends EventEmitter {
     }
 
     private eventToJson(ev: MatrixEvent): IEventWithRoomId {
-        const jsonEvent: any = ev.toJSON();
-        const e = ev.isEncrypted() ? jsonEvent.decrypted : jsonEvent;
+        const e = ev.getEffectiveEvent() as any;
 
         if (ev.isEncrypted()) {
             // Let us store some additional data so we can re-verify the event.