diff --git a/client-spark/common/src/main/java/org/apache/spark/shuffle/reader/RssShuffleDataIterator.java b/client-spark/common/src/main/java/org/apache/spark/shuffle/reader/RssShuffleDataIterator.java
index 478460bc38..c905d27c66 100644
--- a/client-spark/common/src/main/java/org/apache/spark/shuffle/reader/RssShuffleDataIterator.java
+++ b/client-spark/common/src/main/java/org/apache/spark/shuffle/reader/RssShuffleDataIterator.java
@@ -158,8 +158,8 @@ private int uncompress(CompressedShuffleBlock rawBlock, ByteBuffer rawData) {
       unCompressedBytesLength += uncompressedLen;
       long decompressDuration = System.currentTimeMillis() - startDecompress;
       decompressTime += decompressDuration;
-      // ByteBuffer's limit may not uncompressDataLength after using compress method.
-      // So we need set limit here.
+      // uncompressedData's limit is not updated by `codec.decompress`, however this information is used
+      // by `createKVIterator`. Update limit here.
       uncompressedData.limit(uncompressedData.position() + uncompressedLen);
     } else {
       uncompressedData = rawData;