diff --git a/storage/rocksdb/rdb_index_merge.h b/storage/rocksdb/rdb_index_merge.h
index afe7e09612ca244140e0d026e35b2cea44f83787..77f4e0fd1b4ae66bdc435fcbdbf65f1a0440b0aa 100644
--- a/storage/rocksdb/rdb_index_merge.h
+++ b/storage/rocksdb/rdb_index_merge.h
@@ -39,3 +39,6 @@ namespace myrocks {
 #define RDB_MERGE_REC_DELIMITER sizeof(size_t)
 #define RDB_MERGE_KEY_DELIMITER RDB_MERGE_REC_DELIMITER
 #define RDB_MERGE_VAL_DELIMITER RDB_MERGE_REC_DELIMITER
+
+class Rdb_key_def;
+class Rdb_tbl_def;
\ No newline at end of file