diff --git a/src/java/com/threerings/resource/ResourceBundle.java b/src/java/com/threerings/resource/ResourceBundle.java
index 2bcea6711..2e3b72ed3 100644
--- a/src/java/com/threerings/resource/ResourceBundle.java
+++ b/src/java/com/threerings/resource/ResourceBundle.java
@@ -1,5 +1,5 @@
 //
-// $Id: ResourceBundle.java,v 1.17 2003/06/18 16:54:17 mdb Exp $
+// $Id: ResourceBundle.java,v 1.18 2003/06/19 01:12:59 ray Exp $
 
 package com.threerings.resource;
 
@@ -69,6 +69,16 @@ public class ResourceBundle
         return _source;
     }
 
+    /**
+     * @return true if the bundle is fully downloaded and successfully
+     * unpacked.
+     */
+    public boolean isUnpacked ()
+    {
+        return (_source.exists() && (_unpacked != null) &&
+            (_unpacked.lastModified() == _source.lastModified()));
+    }
+
     /**
      * Called by the resource manager once it has ensured that our
      * resource jar file is up to date and ready for reading.