diff --git a/types/chromecast-caf-receiver/cast.framework.messages.d.ts b/types/chromecast-caf-receiver/cast.framework.messages.d.ts
index 366e02d707..0ff76d9bb1 100644
--- a/types/chromecast-caf-receiver/cast.framework.messages.d.ts
+++ b/types/chromecast-caf-receiver/cast.framework.messages.d.ts
@@ -1419,7 +1419,7 @@ export interface MediaInformation {
     /**
      * The media metadata.
      */
-    metadata: 
+    metadata?: 
     | MediaMetadata 
     | GenericMediaMetadata 
     | MovieMediaMetadata