diff --git a/protocol/src/main/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/QueryResult.java b/protocol/src/main/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/QueryResult.java
index 69043709de..5deb7e0f56 100644
--- a/protocol/src/main/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/QueryResult.java
+++ b/protocol/src/main/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/QueryResult.java
@@ -54,7 +54,8 @@ public int size() {
   /**
    * Parse column name from results.
    *
-   * @return mapping from column names to its expression type
+   * @return mapping from column names to its expression type.
+   *        note that column name could be original name or its alias if any.
    */
   public Map<String, String> columnNameTypes() {
     Map<String, String> colNameTypes = new LinkedHashMap<>();