diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/BPOfferService.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/BPOfferService.java
index dcfbfbb42e69c..0c061990bde9f 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/BPOfferService.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/BPOfferService.java
@@ -81,7 +81,7 @@ class BPOfferService {
    * this can be null. If non-null, this must always refer to a member
    * of the {@link #bpServices} list.
    */
-  private BPServiceActor bpServiceToActive = null;
+  private volatile BPServiceActor bpServiceToActive = null;
   
   /**
    * The list of all actors for namenodes in this nameservice, regardless