diff --git a/packages/core/src/storage/docStore/SimpleDocumentStore.ts b/packages/core/src/storage/docStore/SimpleDocumentStore.ts
index c05d93424..c1dfad208 100644
--- a/packages/core/src/storage/docStore/SimpleDocumentStore.ts
+++ b/packages/core/src/storage/docStore/SimpleDocumentStore.ts
@@ -7,7 +7,6 @@ import {
   DEFAULT_PERSIST_DIR,
 } from "../constants";
 import { SimpleKVStore } from "../kvStore/SimpleKVStore";
-import { BaseInMemoryKVStore } from "../kvStore/types";
 import { KVDocumentStore } from "./KVDocumentStore";
 
 type SaveDict = Record<string, any>;
@@ -55,11 +54,8 @@ export class SimpleDocumentStore extends KVDocumentStore {
     ),
     fs?: GenericFileSystem,
   ): Promise<void> {
-    fs = fs || defaultFS;
-    if (
-      _.isObject(this.kvStore) &&
-      this.kvStore instanceof BaseInMemoryKVStore
-    ) {
+    fs = fs || DEFAULT_FS;
+    if (_.isObject(this.kvStore) && this.kvStore instanceof SimpleKVStore) {
       await this.kvStore.persist(persistPath, fs);
     }
   }