diff --git a/packages/firebase-database/index.ios.ts b/packages/firebase-database/index.ios.ts
index a64fe85d..6a3f105b 100644
--- a/packages/firebase-database/index.ios.ts
+++ b/packages/firebase-database/index.ios.ts
@@ -378,7 +378,7 @@ export class Reference extends Query implements IReference {
           onComplete?.(err);
           reject(err);
         } else {
-          onComplete(null);
+          onComplete?.(null);
           resolve();
         }
       });