diff --git a/sync/bme-sync.js b/sync/bme-sync.js
index fc048f8..ff915cf 100644
--- a/sync/bme-sync.js
+++ b/sync/bme-sync.js
@@ -1105,6 +1105,35 @@ function buildManualBackupSnapshot(snapshot = {}, chatId = "") {
   };
 }
 
+function markManualBackupHistoryForLocalRebind(snapshot = {}, chatId = "") {
+  const normalizedSnapshot = normalizeSyncSnapshot(snapshot, chatId);
+  const meta = toSerializableData(normalizedSnapshot.meta, {});
+  const historyState = normalizeRuntimeHistoryMeta(
+    meta[RUNTIME_HISTORY_META_KEY],
+    chatId,
+  );
+  const lastProcessedAssistantFloor = Number(
+    historyState.lastProcessedAssistantFloor,
+  );
+
+  historyState.processedMessageHashes = {};
+  historyState.processedMessageHashesNeedRefresh =
+    Number.isFinite(lastProcessedAssistantFloor) &&
+    lastProcessedAssistantFloor >= 0;
+  meta[RUNTIME_HISTORY_META_KEY] = historyState;
+
+  return {
+    meta,
+    nodes: toSerializableData(normalizedSnapshot.nodes, []),
+    edges: toSerializableData(normalizedSnapshot.edges, []),
+    tombstones: toSerializableData(normalizedSnapshot.tombstones, []),
+    state: toSerializableData(normalizedSnapshot.state, {
+      lastProcessedFloor: -1,
+      extractionCount: 0,
+    }),
+  };
+}
+
 function mergeRuntimeHistoryMeta(localMeta = {}, remoteMeta = {}, options = {}) {
   const localHistory = normalizeRuntimeHistoryMeta(localMeta, options.chatId);
   const remoteHistory = normalizeRuntimeHistoryMeta(remoteMeta, options.chatId);
@@ -2024,7 +2053,10 @@ export async function restoreFromServer(chatId, options = {}) {
       };
     }
 
-    const snapshot = normalizeSyncSnapshot(envelope.snapshot, normalizedChatId);
+    const snapshot = markManualBackupHistoryForLocalRebind(
+      envelope.snapshot,
+      normalizedChatId,
+    );
     if (normalizeChatId(snapshot.meta?.chatId) !== normalizedChatId) {
       return {
         restored: false,
diff --git a/tests/indexeddb-sync.mjs b/tests/indexeddb-sync.mjs
index 1ac5374..dc36c20 100644
--- a/tests/indexeddb-sync.mjs
+++ b/tests/indexeddb-sync.mjs
@@ -623,6 +623,15 @@ async function testManualBackupAndRestoreFlow() {
         chatId: "chat-backup-flow",
         lastProcessedAssistantFloor: 4,
         extractionCount: 2,
+        processedMessageHashVersion: 2,
+        processedMessageHashes: {
+          0: "hash-0",
+          1: "hash-1",
+          2: "hash-2",
+          3: "hash-3",
+          4: "hash-4",
+        },
+        processedMessageHashesNeedRefresh: false,
       },
       runtimeBatchJournal: [
         { id: "journal-1", processedRange: [0, 0], createdAt: 11 },
@@ -677,6 +686,20 @@ async function testManualBackupAndRestoreFlow() {
       retainedCount: 4,
     },
   );
+  assert.deepEqual(
+    backupPayload.snapshot.meta.runtimeHistoryState.processedMessageHashes,
+    {
+      0: "hash-0",
+      1: "hash-1",
+      2: "hash-2",
+      3: "hash-3",
+      4: "hash-4",
+    },
+  );
+  assert.equal(
+    backupPayload.snapshot.meta.runtimeHistoryState.processedMessageHashesNeedRefresh,
+    false,
+  );
   const backupUploadLog = logs.uploadedPayloads.find(
     (entry) => entry.name === backupResult.filename,
   );
@@ -725,6 +748,15 @@ async function testManualBackupAndRestoreFlow() {
       retainedCount: 4,
     },
   );
+  assert.deepEqual(db.snapshot.meta.runtimeHistoryState.processedMessageHashes, {});
+  assert.equal(
+    db.snapshot.meta.runtimeHistoryState.processedMessageHashesNeedRefresh,
+    true,
+  );
+  assert.equal(
+    db.snapshot.meta.runtimeHistoryState.lastProcessedAssistantFloor,
+    4,
+  );
   assert.ok(Number(db.meta.get("lastBackupRestoredAt")) > 0);
   const safetyStatus = await getRestoreSafetySnapshotStatus(
     "chat-backup-flow",