diff --git a/processing/src/main/java/org/apache/druid/query/groupby/GroupingEngine.java b/processing/src/main/java/org/apache/druid/query/groupby/GroupingEngine.java
index 3938516ba363..0c419055c5fe 100644
--- a/processing/src/main/java/org/apache/druid/query/groupby/GroupingEngine.java
+++ b/processing/src/main/java/org/apache/druid/query/groupby/GroupingEngine.java
@@ -950,7 +950,10 @@ private static Iterator<ResultRow> summaryRowIterator(GroupByQuery q)
     List<AggregatorFactory> aggSpec = q.getAggregatorSpecs();
     ResultRow resultRow = ResultRow.create(q.getResultRowSizeWithPostAggregators());
     for (int i = 0; i < aggSpec.size(); i++) {
-      resultRow.set(i, aggSpec.get(i).factorize(new AllNullColumnSelectorFactory()).get());
+      resultRow.set(
+          q.getResultRowAggregatorStart() + i,
+          aggSpec.get(i).factorize(new AllNullColumnSelectorFactory()).get()
+      );
     }
     Map<String, Object> map = resultRow.toMap(q);
     for (int i = 0; i < q.getPostAggregatorSpecs().size(); i++) {