diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/ElasticByteBufferPool.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/ElasticByteBufferPool.java
index c4b4491ec3a..694fcbebcf6 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/ElasticByteBufferPool.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/ElasticByteBufferPool.java
@@ -18,6 +18,7 @@
 package org.apache.hadoop.io;
 
 import com.google.common.collect.ComparisonChain;
+import org.apache.commons.lang.builder.HashCodeBuilder;
 
 import java.nio.ByteBuffer;
 import java.util.Map;
@@ -55,6 +56,9 @@ public int compareTo(Key other) {
 
     @Override
     public boolean equals(Object rhs) {
+      if (rhs == null) {
+        return false;
+      }
       try {
         Key o = (Key)rhs;
         return (compareTo(o) == 0);
@@ -62,6 +66,14 @@ public boolean equals(Object rhs) {
         return false;
       }
     }
+
+    @Override
+    public int hashCode() {
+      return new HashCodeBuilder().
+          append(capacity).
+          append(insertionTime).
+          toHashCode();
+    }
   }
 
   private final TreeMap<Key, ByteBuffer> buffers =