diff --git a/internal/masterservice/meta_table.go b/internal/masterservice/meta_table.go
index f701c4ace8..7df93e84b7 100644
--- a/internal/masterservice/meta_table.go
+++ b/internal/masterservice/meta_table.go
@@ -898,7 +898,7 @@ func (mt *metaTable) GetIndexByName(collName string, fieldName string, indexName
 	if !ok {
 		return nil, fmt.Errorf("collection %s not found", collName)
 	}
-	fieldSchema, err := mt.GetFieldSchema(collName, fieldName)
+	fieldSchema, err := mt.unlockGetFieldSchema(collName, fieldName)
 	if err != nil {
 		return nil, err
 	}