Index: trunk/src/org/openstreetmap/josm/data/UndoRedoHandler.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/UndoRedoHandler.java	(revision 13738)
+++ trunk/src/org/openstreetmap/josm/data/UndoRedoHandler.java	(revision 13739)
@@ -111,4 +111,5 @@
     public static final class CommandAddedEvent extends CommandQueueEvent {
 
+        private static final long serialVersionUID = 1L;
         private final Command cmd;
 
@@ -138,4 +139,5 @@
     public static final class CommandQueueCleanedEvent extends CommandQueueEvent {
 
+        private static final long serialVersionUID = 1L;
         private final DataSet ds;
 
@@ -165,4 +167,5 @@
     public static final class CommandUndoneEvent extends CommandQueueEvent {
 
+        private static final long serialVersionUID = 1L;
         private final Command cmd;
 
@@ -192,4 +195,5 @@
     public static final class CommandRedoneEvent extends CommandQueueEvent {
 
+        private static final long serialVersionUID = 1L;
         private final Command cmd;