diff --git a/xos/tosca/resources/xosresource.py b/xos/tosca/resources/xosresource.py
index 2268024..4e8d041 100644
--- a/xos/tosca/resources/xosresource.py
+++ b/xos/tosca/resources/xosresource.py
@@ -131,7 +131,7 @@
 
             v = self.try_intrinsic_function(v)
 
-            if v:
+            if v is not None:
                 args[prop] = v
 
         return args
@@ -147,7 +147,12 @@
         self.postprocess(xos_obj)
 
     def update(self, obj):
-        pass
+        return # XXX this doesn't work yet
+
+        xos_args = self.get_xos_args()
+        for (k,v) in xos_args:
+            setattr(obj, k)
+        obj.save()
 
     def delete(self, obj):
         if (self.can_delete(obj)):