Index: Twisted/twisted/web2/dav/xattrprops.py
===================================================================
--- Twisted/twisted/web2/dav/xattrprops.py	(revision 17097)
+++ Twisted/twisted/web2/dav/xattrprops.py	(working copy)
@@ -59,7 +59,7 @@
     # Dead properties are stored as extended attributes on disk.  In order to
     # avoid conflicts with other attributes, prefix dead property names.
     #
-    deadPropertyXattrPrefix = "WebDAV:"
+    deadPropertyXattrPrefix = "user.WebDAV."
 
     def _encode(clazz, name):
         #