diff --git a/core/trino-main/src/test/java/io/trino/operator/BenchmarkGroupByHash.java b/core/trino-main/src/test/java/io/trino/operator/BenchmarkGroupByHash.java
index 0555de661f89..b020f26417d8 100644
--- a/core/trino-main/src/test/java/io/trino/operator/BenchmarkGroupByHash.java
+++ b/core/trino-main/src/test/java/io/trino/operator/BenchmarkGroupByHash.java
@@ -290,7 +290,7 @@ private static List<Page> createVarcharPages(int positionCount, int groupCount,
         PageBuilder pageBuilder = new PageBuilder(types);
         for (int position = 0; position < positionCount; position++) {
             int rand = ThreadLocalRandom.current().nextInt(groupCount);
-            Slice value = Slices.wrappedBuffer(ByteBuffer.allocate(4).putInt(rand));
+            Slice value = Slices.wrappedBuffer(ByteBuffer.allocate(4).putInt(rand).flip());
             pageBuilder.declarePosition();
             for (int channel = 0; channel < channelCount; channel++) {
                 VARCHAR.writeSlice(pageBuilder.getBlockBuilder(channel), value);