diff --git a/src/main/java/com/threerings/presents/dobj/AttributeChangedEvent.java b/src/main/java/com/threerings/presents/dobj/AttributeChangedEvent.java
index ce1c011f0..7e6ffe1ee 100644
--- a/src/main/java/com/threerings/presents/dobj/AttributeChangedEvent.java
+++ b/src/main/java/com/threerings/presents/dobj/AttributeChangedEvent.java
@@ -44,19 +44,10 @@ public class AttributeChangedEvent extends NamedEvent
      * @param value the new value of the attribute (in the case of primitive types, the
      * reflection-defined object-alternative is used).
      */
-    public AttributeChangedEvent (int targetOid, String name, Object value, Object oldValue)
+    public AttributeChangedEvent (int targetOid, String name, Object value)
     {
         super(targetOid, name);
         _value = value;
-        _oldValue = oldValue;
-    }
-
-    /** For unserialization. */
-    public AttributeChangedEvent ()
-    {
-        super(0, null);
-        // we can't allow our primary ctor to be called during unserialization, or it will wipe out
-        // the hackery we do with _oldValue
     }
 
     /**
@@ -182,6 +173,12 @@ public class AttributeChangedEvent extends NamedEvent
         StringUtil.toString(buf, _value);
     }
 
+    protected AttributeChangedEvent setOldValue (Object oldValue)
+    {
+        _oldValue = oldValue;
+        return this;
+    }
+
     protected Object _value;
     protected transient Object _oldValue = UNSET_OLD_VALUE;
 }
diff --git a/src/main/java/com/threerings/presents/dobj/DObject.java b/src/main/java/com/threerings/presents/dobj/DObject.java
index 49b910658..79a9549e1 100644
--- a/src/main/java/com/threerings/presents/dobj/DObject.java
+++ b/src/main/java/com/threerings/presents/dobj/DObject.java
@@ -871,7 +871,8 @@ public class DObject
         String name, Object value, Object oldValue, Transport transport)
     {
         // dispatch an attribute changed event
-        postEvent(new AttributeChangedEvent(_oid, name, value, oldValue).setTransport(transport));
+        postEvent(new AttributeChangedEvent(_oid, name, value).
+                  setOldValue(oldValue).setTransport(transport));
     }
 
     /**
@@ -889,8 +890,8 @@ public class DObject
         String name, int index, Object value, Object oldValue, Transport transport)
     {
         // dispatch an attribute changed event
-        postEvent(new ElementUpdatedEvent(_oid, name, value, oldValue, index).
-                  setTransport(transport));
+        postEvent(new ElementUpdatedEvent(_oid, name, value, index).
+                  setOldValue(oldValue).setTransport(transport));
     }
 
     /**
@@ -962,7 +963,7 @@ public class DObject
             }
         }
         // dispatch an entry removed event
-        postEvent(new EntryRemovedEvent<T>(_oid, name, key, oldEntry));
+        postEvent(new EntryRemovedEvent<T>(_oid, name, key).setOldEntry(oldEntry));
     }
 
     /**
@@ -989,7 +990,8 @@ public class DObject
             }
         }
         // dispatch an entry updated event
-        postEvent(new EntryUpdatedEvent<T>(_oid, name, entry, oldEntry).setTransport(transport));
+        postEvent(new EntryUpdatedEvent<T>(_oid, name, entry).
+                  setOldEntry(oldEntry).setTransport(transport));
     }
 
     protected boolean isAuthoritative ()
diff --git a/src/main/java/com/threerings/presents/dobj/ElementUpdatedEvent.java b/src/main/java/com/threerings/presents/dobj/ElementUpdatedEvent.java
index ba91ddb4b..a87e89908 100644
--- a/src/main/java/com/threerings/presents/dobj/ElementUpdatedEvent.java
+++ b/src/main/java/com/threerings/presents/dobj/ElementUpdatedEvent.java
@@ -43,18 +43,23 @@ public class ElementUpdatedEvent extends NamedEvent
      * @param name the name of the attribute (data member) for which an element has changed.
      * @param value the new value of the element (in the case of primitive types, the
      * reflection-defined object-alternative is used).
-     * @param ovalue the previous value of the element (in the case of primitive types, the
-     * reflection-defined object-alternative is used).
      * @param index the index in the array of the updated element.
      */
-    public ElementUpdatedEvent (int targetOid, String name, Object value, Object ovalue, int index)
+    public ElementUpdatedEvent (int targetOid, String name, Object value, int index)
     {
         super(targetOid, name);
         _value = value;
-        _oldValue = ovalue;
         _index = index;
     }
 
+    /** For unserialization. */
+    public ElementUpdatedEvent ()
+    {
+        super(0, null);
+        // we can't allow our primary ctor to be called during unserialization, or it will wipe out
+        // the hackery we do with _oldValue
+    }
+
     /**
      * Returns the new value of the element.
      */
@@ -180,6 +185,12 @@ public class ElementUpdatedEvent extends NamedEvent
         buf.append(", index=").append(_index);
     }
 
+    protected ElementUpdatedEvent setOldValue (Object oldValue)
+    {
+        _oldValue = oldValue;
+        return this;
+    }
+
     protected Object _value;
     protected int _index;
     protected transient Object _oldValue = UNSET_OLD_VALUE;
diff --git a/src/main/java/com/threerings/presents/dobj/EntryRemovedEvent.java b/src/main/java/com/threerings/presents/dobj/EntryRemovedEvent.java
index 1cca07698..d1f018c31 100644
--- a/src/main/java/com/threerings/presents/dobj/EntryRemovedEvent.java
+++ b/src/main/java/com/threerings/presents/dobj/EntryRemovedEvent.java
@@ -42,21 +42,11 @@ public class EntryRemovedEvent<T extends DSet.Entry> extends EntryEvent<T>
      * @param targetOid the object id of the object from whose set we will remove an entry.
      * @param name the name of the attribute from which to remove the specified entry.
      * @param key the entry key that identifies the entry to remove.
-     * @param oldEntry the previous value of the entry.
      */
-    public EntryRemovedEvent (int targetOid, String name, Comparable<?> key, T oldEntry)
+    public EntryRemovedEvent (int targetOid, String name, Comparable<?> key)
     {
         super(targetOid, name);
         _key = key;
-        _oldEntry = oldEntry;
-    }
-
-    /** For unserialization. */
-    public EntryRemovedEvent ()
-    {
-        super(0, null);
-        // we can't allow our primary ctor to be called during unserialization, or it will wipe out
-        // the hackery we do with _oldEntry
     }
 
     @Override
@@ -125,6 +115,12 @@ public class EntryRemovedEvent<T extends DSet.Entry> extends EntryEvent<T>
         buf.append(", key=").append(_key);
     }
 
+    protected EntryRemovedEvent setOldEntry (T oldEntry)
+    {
+        _oldEntry = oldEntry;
+        return this;
+    }
+
     protected Comparable<?> _key;
 
     @SuppressWarnings("unchecked")
diff --git a/src/main/java/com/threerings/presents/dobj/EntryUpdatedEvent.java b/src/main/java/com/threerings/presents/dobj/EntryUpdatedEvent.java
index 7c2da4493..9f7ac1818 100644
--- a/src/main/java/com/threerings/presents/dobj/EntryUpdatedEvent.java
+++ b/src/main/java/com/threerings/presents/dobj/EntryUpdatedEvent.java
@@ -43,21 +43,11 @@ public class EntryUpdatedEvent<T extends DSet.Entry> extends EntryEvent<T>
      * @param targetOid the object id of the object to whose set we will add an entry.
      * @param name the name of the attribute in which to update the specified entry.
      * @param entry the entry to update.
-     * @param oldEntry the previous value of the entry.
      */
-    public EntryUpdatedEvent (int targetOid, String name, T entry, T oldEntry)
+    public EntryUpdatedEvent (int targetOid, String name, T entry)
     {
         super(targetOid, name);
         _entry = entry;
-        _oldEntry = oldEntry;
-    }
-
-    /** For unserialization. */
-    public EntryUpdatedEvent ()
-    {
-        super(0, null);
-        // we can't allow our primary ctor to be called during unserialization, or it will wipe out
-        // the hackery we do with _oldEntry
     }
 
     @Override
@@ -128,6 +118,12 @@ public class EntryUpdatedEvent<T extends DSet.Entry> extends EntryEvent<T>
         StringUtil.toString(buf, _entry);
     }
 
+    protected EntryUpdatedEvent setOldEntry (T oldEntry)
+    {
+        _oldEntry = oldEntry;
+        return this;
+    }
+
     protected T _entry;
 
     @SuppressWarnings("unchecked")