diff --git a/packages/common/nbstore/src/impls/idb/v1/doc.ts b/packages/common/nbstore/src/impls/idb/v1/doc.ts
index 82b88384d1..1fe145c249 100644
--- a/packages/common/nbstore/src/impls/idb/v1/doc.ts
+++ b/packages/common/nbstore/src/impls/idb/v1/doc.ts
@@ -17,6 +17,13 @@ import {
 import { getIdConverter } from '../../../utils/id-converter';
 import { DocIDBConnection } from './db';
 
+/**
+ * We use a fixed timestamp in v1 because the v1 should never be changed.
+ * This date is chosen because it is large enough to overwrite some previous error data.
+ * In our sync storage, only a larger timestamp can overwrite smaller one.
+ */
+const CONST_TIMESTAMP = new Date(1893456000000);
+
 /**
  * @deprecated readonly
  */
@@ -45,7 +52,14 @@ export class IndexedDBV1DocStorage extends DocStorageBase {
       return null;
     }
     const oldId = (await this.getIdConverter()).newIdToOldId(docId);
-    return this.rawGetDoc(oldId);
+    const rawDoc = await this.rawGetDoc(oldId);
+    return rawDoc
+      ? {
+          docId: rawDoc.docId,
+          bin: rawDoc.bin,
+          timestamp: CONST_TIMESTAMP,
+        }
+      : null;
   }
 
   protected override async getDocSnapshot() {
@@ -54,7 +68,7 @@ export class IndexedDBV1DocStorage extends DocStorageBase {
 
   override async pushDocUpdate(update: DocUpdate) {
     // no more writes to old db
-    return { docId: update.docId, timestamp: new Date() };
+    return { docId: update.docId, timestamp: CONST_TIMESTAMP };
   }
 
   override async deleteDoc(docId: string) {
@@ -110,7 +124,7 @@ export class IndexedDBV1DocStorage extends DocStorageBase {
     );
 
     return Object.fromEntries(
-      oldIds.map(id => [idConverter.oldIdToNewId(id), new Date(1)])
+      oldIds.map(id => [idConverter.oldIdToNewId(id), CONST_TIMESTAMP])
     );
   }
 
diff --git a/packages/common/nbstore/src/impls/sqlite/v1/doc.ts b/packages/common/nbstore/src/impls/sqlite/v1/doc.ts
index 8100912c87..8027feb212 100644
--- a/packages/common/nbstore/src/impls/sqlite/v1/doc.ts
+++ b/packages/common/nbstore/src/impls/sqlite/v1/doc.ts
@@ -9,6 +9,13 @@ import { isEmptyUpdate } from '../../../utils/is-empty-update';
 import type { SpaceType } from '../../../utils/universal-id';
 import { apis } from './db';
 
+/**
+ * We use a fixed timestamp in v1 because the v1 should never be changed.
+ * This date is chosen because it is large enough to overwrite some previous error data.
+ * In our sync storage, only a larger timestamp can overwrite smaller one.
+ */
+const CONST_TIMESTAMP = new Date(1893456000000);
+
 /**
  * @deprecated readonly
  */
@@ -34,7 +41,7 @@ export class SqliteV1DocStorage extends DocStorageBase<{
 
   override async pushDocUpdate(update: DocUpdate) {
     // no more writes
-    return { docId: update.docId, timestamp: new Date() };
+    return { docId: update.docId, timestamp: CONST_TIMESTAMP };
   }
 
   override async getDoc(docId: string) {
@@ -52,7 +59,7 @@ export class SqliteV1DocStorage extends DocStorageBase<{
     return {
       docId,
       bin,
-      timestamp: new Date(),
+      timestamp: CONST_TIMESTAMP,
     };
   }
 
@@ -69,8 +76,9 @@ export class SqliteV1DocStorage extends DocStorageBase<{
     const idConverter = await this.getIdConverter();
 
     return timestamps.reduce(
-      (ret, { docId, timestamp }) => {
-        ret[idConverter.oldIdToNewId(docId ?? this.options.id)] = timestamp;
+      (ret, { docId }) => {
+        ret[idConverter.oldIdToNewId(docId ?? this.options.id)] =
+          CONST_TIMESTAMP;
         return ret;
       },
       {} as Record<string, Date>
diff --git a/packages/common/nbstore/src/sync/doc/peer.ts b/packages/common/nbstore/src/sync/doc/peer.ts
index b38e7ee483..426498199f 100644
--- a/packages/common/nbstore/src/sync/doc/peer.ts
+++ b/packages/common/nbstore/src/sync/doc/peer.ts
@@ -199,7 +199,8 @@ export class DocSyncPeer {
       throwIfAborted(signal);
       if (
         !this.remote.isReadonly &&
-        (pushedClock === null || pushedClock !== clock?.timestamp)
+        clock &&
+        (pushedClock === null || pushedClock !== clock.timestamp)
       ) {
         await this.jobs.pullAndPush(docId, signal);
       } else {