diff --git a/hadoop-common-project/hadoop-common/CHANGES.txt b/hadoop-common-project/hadoop-common/CHANGES.txt
index bab2220cf8..6bedd4ddb5 100644
--- a/hadoop-common-project/hadoop-common/CHANGES.txt
+++ b/hadoop-common-project/hadoop-common/CHANGES.txt
@@ -753,6 +753,9 @@ Release 2.7.0 - UNRELEASED
     HADOOP-11493. Fix some typos in kms-acls.xml description.
     (Charles Lamb via aajisaka)
 
+    HADOOP-11507 Hadoop RPC Authentication problem with different user locale.
+    (Talat UYARER via stevel)
+
 Release 2.6.0 - 2014-11-18
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/SaslPropertiesResolver.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/SaslPropertiesResolver.java
index c4fc965a95..0b49cfbc44 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/SaslPropertiesResolver.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/SaslPropertiesResolver.java
@@ -18,6 +18,7 @@
 package org.apache.hadoop.security;
 
 import java.net.InetAddress;
+import java.util.Locale;
 import java.util.Map;
 import java.util.TreeMap;
 
@@ -65,7 +66,7 @@ public void setConf(Configuration conf) {
         CommonConfigurationKeysPublic.HADOOP_RPC_PROTECTION,
         QualityOfProtection.AUTHENTICATION.toString());
     for (int i=0; i < qop.length; i++) {
-      qop[i] = QualityOfProtection.valueOf(qop[i].toUpperCase()).getSaslQop();
+      qop[i] = QualityOfProtection.valueOf(qop[i].toUpperCase(Locale.ENGLISH)).getSaslQop();
     }
     properties.put(Sasl.QOP, StringUtils.join(",", qop));
     properties.put(Sasl.SERVER_AUTH, "true");