diff --git a/sql/core/src/main/scala/org/apache/spark/sql/GroupedData.scala b/sql/core/src/main/scala/org/apache/spark/sql/GroupedData.scala
index ee7150cbbfbca590b2c98127aae349c07650a2c9..abd531c4ba5417203c6a720c3983244b813e6994 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/GroupedData.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/GroupedData.scala
@@ -304,7 +304,7 @@ class GroupedData protected[sql](
     // Get the distinct values of the column and sort them so its consistent
     val values = df.select(pivotColumn)
       .distinct()
-      .sort(pivotColumn)
+      .sort(pivotColumn)  // ensure that the output columns are in a consistent logical order
       .map(_.get(0))
       .take(maxValues + 1)
       .toSeq