diff --git a/src/Disks/ObjectStorages/CommonPathPrefixKeyGenerator.h b/src/Disks/ObjectStorages/CommonPathPrefixKeyGenerator.h
index c0622c3e63a..68a390a51b6 100644
--- a/src/Disks/ObjectStorages/CommonPathPrefixKeyGenerator.h
+++ b/src/Disks/ObjectStorages/CommonPathPrefixKeyGenerator.h
@@ -20,6 +20,7 @@ namespace DB
 class CommonPathPrefixKeyGenerator : public IObjectStorageKeysGenerator
 {
 public:
+    /// Local to remote path map.
     using PathMap = std::unordered_map<std::string, std::string>;
 
     explicit CommonPathPrefixKeyGenerator(String key_prefix_, SharedMutex & shared_mutex_, std::weak_ptr<PathMap> path_map_);