diff --git a/hadoop-common-project/hadoop-common/CHANGES.txt b/hadoop-common-project/hadoop-common/CHANGES.txt
index e0635f7a76c..e38136554f8 100644
--- a/hadoop-common-project/hadoop-common/CHANGES.txt
+++ b/hadoop-common-project/hadoop-common/CHANGES.txt
@@ -51,8 +51,10 @@ Release 0.23.1 - Unreleased
    HADOOP-7864. Building mvn site with Maven < 3.0.2 causes OOM errors.
    (Andrew Bayer via eli)
 
-    HADOOP-7853. multiple javax security configurations cause conflicts.
-    (daryn via tucu)
+   HADOOP-7853. multiple javax security configurations cause conflicts.
+   (daryn via tucu)
+
+   HADOOP-7854. UGI getCurrentUser is not synchronized. (Daryn Sharp via jitendra)
 
 Release 0.23.0 - 2011-11-01 
 
diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/UserGroupInformation.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/UserGroupInformation.java
index 344c08e2b66..b272e80fac6 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/UserGroupInformation.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/UserGroupInformation.java
@@ -449,7 +449,8 @@ public class UserGroupInformation {
    * @return the current user
    * @throws IOException if login fails
    */
-  public static UserGroupInformation getCurrentUser() throws IOException {
+  public synchronized
+  static UserGroupInformation getCurrentUser() throws IOException {
     AccessControlContext context = AccessController.getContext();
     Subject subject = Subject.getSubject(context);
     if (subject == null || subject.getPrincipals(User.class).isEmpty()) {