diff --git a/bxml/xt.py b/bxml/xt.py
index <HASH>..<HASH> 100644
--- a/bxml/xt.py
+++ b/bxml/xt.py
@@ -41,7 +41,7 @@ class XT:
                         if self.debug==True: self.log("=> match:", expression)
                         ee += m.function(elem, mutable=mutable, **params)
                         break
-        return ee
+        return [e for e in ee if e is not None]
 
     def Element(self, elem, mutable={}, **params):
         """Ensure that the input element is immutable by the transformation. Returns a single element."""
in XT.__call__() only return elements that are not None.