diff --git a/CHANGES.txt b/CHANGES.txt
index 4f3d5940f13..710beb400e7 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -36,6 +36,9 @@ Trunk (unreleased changes)
 
     HADOOP-7059. Remove "unused" warning in native code.  (Noah Watkins via eli)
 
+    HADOOP-7078. Improve javadocs for RawComparator interface.
+    (Harsh J Chouraria via todd)
+
   OPTIMIZATIONS
 
   BUG FIXES
diff --git a/src/java/org/apache/hadoop/io/RawComparator.java b/src/java/org/apache/hadoop/io/RawComparator.java
index 11539442c85..a52190db5f4 100644
--- a/src/java/org/apache/hadoop/io/RawComparator.java
+++ b/src/java/org/apache/hadoop/io/RawComparator.java
@@ -36,6 +36,18 @@ import org.apache.hadoop.io.serializer.DeserializerComparator;
 @InterfaceStability.Stable
 public interface RawComparator<T> extends Comparator<T> {
 
+  /**
+   * Compare two objects in binary.
+   * b1[s1:l1] is the first object, and b2[s2:l2] is the second object.
+   * 
+   * @param b1 The first byte array.
+   * @param s1 The position index in b1. The object under comparison's starting index.
+   * @param l1 The length of the object in b1.
+   * @param b2 The second byte array.
+   * @param s2 The position index in b2. The object under comparison's starting index.
+   * @param l2 The length of the object under comparison in b2.
+   * @return An integer result of the comparison.
+   */
   public int compare(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2);
 
 }