diff --git a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Factories/Index.php b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Factories/Index.php
index 715f98c4177c0..211d3885297ba 100644
--- a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Factories/Index.php
+++ b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Factories/Index.php
@@ -19,7 +19,7 @@ class Index implements FactoryInterface
     /**
      * Default index type.
      */
-    const DEFAULT_INDEX_TYPE = "BTREE";
+    const DEFAULT_INDEX_TYPE = "btree";
 
     /**
      * @var ObjectManagerInterface