diff --git a/core/src/main/java/hudson/model/ItemGroupMixIn.java b/core/src/main/java/hudson/model/ItemGroupMixIn.java
index 57ae57f9b2e7b6bd68c9d0465a5afe97eee73323..51c963004b6c0f0101cc41a8fe486478936f04dc 100644
--- a/core/src/main/java/hudson/model/ItemGroupMixIn.java
+++ b/core/src/main/java/hudson/model/ItemGroupMixIn.java
@@ -93,7 +93,7 @@ public abstract class ItemGroupMixIn {
 
         File[] subdirs = modulesDir.listFiles(new FileFilter() {
             public boolean accept(File child) {
-                return child.isDirectory();
+                return child.isDirectory() && new File(child,"config.xml").exists();
             }
         });
         CopyOnWriteMap.Tree<K,V> configurations = new CopyOnWriteMap.Tree<K,V>();