diff --git a/index.d.ts b/index.d.ts
index 60bddd0..4ce534a 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -131,7 +131,7 @@ export interface ResourceStatus extends ResourceStatusRequired {
     /**
      * When the error occurred
      */
-    errorOccurredAt: number,
+    errorOccurredAt?: number,
 
     /**
      * When a request to fetch, create or update the resource item or list was last made to an external