diff --git a/sugar/activity/bundlebuilder.py b/sugar/activity/bundlebuilder.py
index a5f0f1a2..16e47f78 100644
--- a/sugar/activity/bundlebuilder.py
+++ b/sugar/activity/bundlebuilder.py
@@ -55,7 +55,7 @@ class _DefaultFileList(list):
             self.append('NEWS')
 
 class _ManifestFileList(list):
-    def __init__(self, manifest=None):
+    def __init__(self, manifest):
         self.append(manifest)
 
         f = open(manifest,'r')
@@ -67,7 +67,8 @@ class _ManifestFileList(list):
 
         defaults = _DefaultFileList()
         for path in defaults:
-            self.append(path)
+            if not path in self:
+                self.append(path)
 
 def _extract_bundle(source_file, dest_dir):
         if not os.path.exists(dest_dir):