diff --git a/HISTORY.md b/HISTORY.md
index 6561e520e..567d40d08 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -1,5 +1,7 @@
 # Rocksdb Change Log
 ## Unreleased
+### Public API Changes
+* Change default of BlockBasedTableOptions.format_version to 2. It means default DB created by 4.6 or up cannot be opened by RocksDB version 3.9 or earlier.
 ### New Features
 * Add CompactionPri::kMinOverlappingRatio, a compaction picking mode friendly to write amplification.
 * Deprecate Iterator::IsKeyPinned() and replace it with Iterator::GetProperty() with prop_name="rocksdb.iterator.is.key.pinned"
diff --git a/include/rocksdb/table.h b/include/rocksdb/table.h
index 157d4274c..cb4d850e8 100644
--- a/include/rocksdb/table.h
+++ b/include/rocksdb/table.h
@@ -166,7 +166,7 @@ struct BlockBasedTableOptions {
   // this.
   // This option only affects newly written tables. When reading exising tables,
   // the information about version is read from the footer.
-  uint32_t format_version = 0;
+  uint32_t format_version = 2;
 };
 
 // Table Properties that are specific to block-based table properties.