diff --git a/src/Storages/ObjectStorageQueue/ObjectStorageQueueSource.cpp b/src/Storages/ObjectStorageQueue/ObjectStorageQueueSource.cpp
index 955e49bc2bf..1939ea0a66f 100644
--- a/src/Storages/ObjectStorageQueue/ObjectStorageQueueSource.cpp
+++ b/src/Storages/ObjectStorageQueue/ObjectStorageQueueSource.cpp
@@ -111,10 +111,12 @@ void ObjectStorageQueueSource::FileIterator::returnForRetry(Source::ObjectInfoPt
     if (metadata->useBucketsForProcessing())
     {
         const auto bucket = metadata->getBucketForPath(object_info->relative_path);
+        std::lock_guard lock(mutex);
         listed_keys_cache[bucket].keys.emplace_front(object_info);
     }
     else
     {
+        std::lock_guard lock(mutex);
         objects_to_retry.push_back(object_info);
     }
 }