diff --git a/src/as/com/threerings/presents/data/ClientObject.as b/src/as/com/threerings/presents/data/ClientObject.as
index 2826be672..7b2283e1e 100644
--- a/src/as/com/threerings/presents/data/ClientObject.as
+++ b/src/as/com/threerings/presents/data/ClientObject.as
@@ -21,8 +21,6 @@
 
 package com.threerings.presents.data {
 
-import mx.utils.ObjectUtil;
-
 import com.threerings.presents.dobj.DObject;
 import com.threerings.presents.dobj.DSet;
 import com.threerings.presents.dobj.DSet_Entry;
@@ -79,7 +77,7 @@ public class ClientObject extends DObject
     {
         requestAttributeChange(RECEIVERS, value, this.receivers);
         this.receivers = (value == null) ? null
-                                         : (ObjectUtil.copy(value) as DSet);
+                                         : (value.clone() as DSet);
     }
     // AUTO-GENERATED: METHODS END
 
diff --git a/src/as/com/threerings/presents/dobj/DSet.as b/src/as/com/threerings/presents/dobj/DSet.as
index 82ef413c9..6f575911c 100644
--- a/src/as/com/threerings/presents/dobj/DSet.as
+++ b/src/as/com/threerings/presents/dobj/DSet.as
@@ -3,6 +3,7 @@ package com.threerings.presents.dobj {
 import mx.utils.ObjectUtil;
 
 import com.threerings.util.ArrayIterator;
+import com.threerings.util.Cloneable;
 import com.threerings.util.Equalable;
 import com.threerings.util.Iterator;
 import com.threerings.util.StringBuilder;
@@ -32,7 +33,7 @@ import com.threerings.io.TypedArray;
  * a {@link Streamable} type.
  */
 public class DSet
-    implements Streamable
+    implements Cloneable, Streamable
 {
     /**
      * Returns the number of entries in this set.
@@ -189,6 +190,16 @@ public class DSet
         return null;
     }
 
+    // from interface Cloneable
+    public function clone () :Object
+    {
+        var other :DSet = new DSet();
+        for each (var val :DSet_Entry in _entries) {
+            other._entries.push(val);
+        }
+        return other;
+    }
+
     /**
      * Generates a string representation of this set instance.
      */