Index: RAMDirectory.java
===================================================================
--- RAMDirectory.java	(revision 409813)
+++ RAMDirectory.java	(working copy)
@@ -18,6 +18,7 @@
 
 import java.io.IOException;
 import java.io.File;
+import java.io.Serializable;
 import java.util.Hashtable;
 import java.util.Enumeration;
 
@@ -30,7 +31,10 @@
  *
  * @version $Id$
  */
-public final class RAMDirectory extends Directory {
+public final class RAMDirectory extends Directory implements Serializable {
+
+  private static final long serialVersionUID = 1l;
+
   Hashtable files = new Hashtable();
 
   /** Constructs an empty {@link Directory}. */
Index: RAMFile.java
===================================================================
--- RAMFile.java	(revision 409813)
+++ RAMFile.java	(working copy)
@@ -17,8 +17,12 @@
  */
 
 import java.util.Vector;
+import java.io.Serializable;
 
-class RAMFile {
+class RAMFile implements Serializable {
+
+  private static final long serialVersionUID = 1l;
+
   Vector buffers = new Vector();
   long length;
   long lastModified = System.currentTimeMillis();