diff --git a/hadoop-mapreduce-project/CHANGES.txt b/hadoop-mapreduce-project/CHANGES.txt
index c8aa10ab572..ec0e49d5891 100644
--- a/hadoop-mapreduce-project/CHANGES.txt
+++ b/hadoop-mapreduce-project/CHANGES.txt
@@ -18,6 +18,9 @@ Release 2.8.0 - UNRELEASED
     MAPREDUCE-4414. Add main methods to JobConf and YarnConfiguration,
     for debug purposes. (Plamen Jeliazkov via harsh)
 
+    MAPREDUCE-5755. MapTask.MapOutputBuffer#compare/swap should have
+    @Override annotation. (ozawa)
+
   OPTIMIZATIONS
 
   BUG FIXES
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/MapTask.java b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/MapTask.java
index 80943178298..c4957b75517 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/MapTask.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/MapTask.java
@@ -1255,6 +1255,7 @@ public class MapTask extends Task {
      * Compare by partition, then by key.
      * @see IndexedSortable#compare
      */
+    @Override
     public int compare(final int mi, final int mj) {
       final int kvi = offsetFor(mi % maxRec);
       final int kvj = offsetFor(mj % maxRec);
@@ -1278,6 +1279,7 @@ public class MapTask extends Task {
      * Swap metadata for items i, j
      * @see IndexedSortable#swap
      */
+    @Override
     public void swap(final int mi, final int mj) {
       int iOff = (mi % maxRec) * METASIZE;
       int jOff = (mj % maxRec) * METASIZE;