diff --git a/src/helma/framework/core/Session.java b/src/helma/framework/core/Session.java
index 8addc5a9..8bb84de4 100644
--- a/src/helma/framework/core/Session.java
+++ b/src/helma/framework/core/Session.java
@@ -32,6 +32,8 @@ import java.util.*;
  */
 public class Session implements Serializable {
 
+    static final long serialVersionUID = -6149094040363012913L;
+    
     transient protected Application app;
     protected String sessionId;