diff --git a/spring-security-kerberos-core/src/main/java/org/springframework/security/kerberos/authentication/JaasSubjectHolder.java b/spring-security-kerberos-core/src/main/java/org/springframework/security/kerberos/authentication/JaasSubjectHolder.java
index f6cee19..673b4bf 100644
--- a/spring-security-kerberos-core/src/main/java/org/springframework/security/kerberos/authentication/JaasSubjectHolder.java
+++ b/spring-security-kerberos-core/src/main/java/org/springframework/security/kerberos/authentication/JaasSubjectHolder.java
@@ -15,6 +15,7 @@
  */
 package org.springframework.security.kerberos.authentication;
 
+import java.io.Serializable;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -30,7 +31,10 @@ import org.springframework.security.kerberos.authentication.sun.SunJaasKerberosC
  * @see SunJaasKerberosClient
  * @see org.springframework.security.kerberos.authentication.KerberosAuthenticationProvider
  */
-public class JaasSubjectHolder {
+public class JaasSubjectHolder implements Serializable {
+
+	private static final long serialVersionUID = 8174713761131577405L;
+
     private Subject jaasSubject;
     private String username;
 
diff --git a/spring-security-kerberos-core/src/main/java/org/springframework/security/kerberos/authentication/KerberosUsernamePasswordAuthenticationToken.java b/spring-security-kerberos-core/src/main/java/org/springframework/security/kerberos/authentication/KerberosUsernamePasswordAuthenticationToken.java
index 06812e3..5df078d 100644
--- a/spring-security-kerberos-core/src/main/java/org/springframework/security/kerberos/authentication/KerberosUsernamePasswordAuthenticationToken.java
+++ b/spring-security-kerberos-core/src/main/java/org/springframework/security/kerberos/authentication/KerberosUsernamePasswordAuthenticationToken.java
@@ -36,7 +36,9 @@ public class KerberosUsernamePasswordAuthenticationToken
         extends UsernamePasswordAuthenticationToken
         implements KerberosAuthentication {
 
-    private final JaasSubjectHolder jaasSubjectHolder;
+    private static final long serialVersionUID = 6327699460703504153L;
+
+	private final JaasSubjectHolder jaasSubjectHolder;
 
     /**
      * <p>Creates an authentication token that holds the username and password, and the Subject