diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index dd9fc310b13..44102c0d476 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -292,6 +292,9 @@ Release 2.5.0 - UNRELEASED
     HDFS-6453. Use Time#monotonicNow to avoid system clock reset.
     (Liang Xie via wang)
 
+    HDFS-6461. Use Time#monotonicNow to compute duration in DataNode#shutDown.
+    (James Thomas via wang)
+
 Release 2.4.1 - UNRELEASED
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java
index 349225460fb..2e542dad4e5 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java
@@ -1228,7 +1228,7 @@ public class DataNode extends Configured
     }
     
     // Record the time of initial notification
-    long timeNotified = Time.now();
+    long timeNotified = Time.monotonicNow();
 
     if (localDataXceiverServer != null) {
       ((DataXceiverServer) this.localDataXceiverServer.getRunnable()).kill();
@@ -1260,8 +1260,9 @@ public class DataNode extends Configured
       while (true) {
         // When shutting down for restart, wait 2.5 seconds before forcing
         // termination of receiver threads.
-        if (!this.shutdownForUpgrade || 
-            (this.shutdownForUpgrade && (Time.now() - timeNotified > 2500))) {
+        if (!this.shutdownForUpgrade ||
+            (this.shutdownForUpgrade && (Time.monotonicNow() - timeNotified
+                > 2500))) {
           this.threadGroup.interrupt();
         }
         LOG.info("Waiting for threadgroup to exit, active threads is " +