diff --git a/CHANGES.txt b/CHANGES.txt
index bb5c19cdee..8d8914086f 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -119,6 +119,9 @@ Trunk (unreleased changes)
     HADOOP-6495.  Identifier should be serialized after the password is
      created In Token constructor (jnp via boryas)
 
+    HADOOP-6518. Makes the UGI honor the env var KRB5CCNAME. 
+    (Owen O'Malley via ddas)
+
   OPTIMIZATIONS
 
   BUG FIXES
diff --git a/src/java/org/apache/hadoop/security/UserGroupInformation.java b/src/java/org/apache/hadoop/security/UserGroupInformation.java
index b3eab89c59..adc03617b7 100644
--- a/src/java/org/apache/hadoop/security/UserGroupInformation.java
+++ b/src/java/org/apache/hadoop/security/UserGroupInformation.java
@@ -241,6 +241,10 @@ private static class HadoopConfiguration
     static {
       USER_KERBEROS_OPTIONS.put("doNotPrompt", "true");
       USER_KERBEROS_OPTIONS.put("useTicketCache", "true");
+      String ticketCache = System.getenv("KRB5CCNAME");
+      if (ticketCache != null) {
+        USER_KERBEROS_OPTIONS.put("ticketCache", ticketCache);
+      }
     }
     private static final AppConfigurationEntry USER_KERBEROS_LOGIN =
       new AppConfigurationEntry(Krb5LoginModule.class.getName(),