diff --git a/src/as/com/threerings/util/ClassUtil.as b/src/as/com/threerings/util/ClassUtil.as
index 97bad3932..72000622a 100644
--- a/src/as/com/threerings/util/ClassUtil.as
+++ b/src/as/com/threerings/util/ClassUtil.as
@@ -21,6 +21,8 @@
 
 package com.threerings.util {
 
+import flash.system.ApplicationDomain;
+
 import flash.utils.describeType;
 import flash.utils.getQualifiedClassName;
 import flash.utils.getDefinitionByName;
@@ -62,9 +64,9 @@ public class ClassUtil
      * Return a new instance that is the same class as the specified
      * object. The class must have a zero-arg constructor.
      */
-    public static function newInstance (obj :Object) :Object
+    public static function newInstance (obj :Object, appDom :ApplicationDomain = null) :Object
     {
-        var clazz :Class = getClass(obj);
+        var clazz :Class = getClass(obj, appDom);
         return new clazz();
     }
 
@@ -73,16 +75,26 @@ public class ClassUtil
         return (getQualifiedClassName(obj1) == getQualifiedClassName(obj2));
     }
 
-    public static function getClass (obj :Object) :Class
+    public static function getClass (obj :Object, appDom :ApplicationDomain = null) :Class
     {
-        return getClassByName(getQualifiedClassName(obj));
+        return getClassByName(getQualifiedClassName(obj), appDom);
     }
 
-    public static function getClassByName (cname :String) :Class
+    public static function getClassByName (cname :String, appDom :ApplicationDomain = null) :Class
     {
         try {
-            // see also ApplicationDomain.currentDomain.getClass(cname)
-            return (getDefinitionByName(cname.replace("::", ".")) as Class);
+            cname = cname.replace("::", ".");
+            if (appDom != null) {
+                try {
+                    var c :Class = appDom.getDefinition(cname) as Class;
+                    if (c != null) {
+                        return c;
+                    }
+                } catch (err :Error) {
+                    // fall through
+                }
+            }
+            return (getDefinitionByName(cname) as Class);
 
         } catch (error :ReferenceError) {
             var log :Log = Log.getLog(ClassUtil);