diff --git a/slixmpp/xmlstream/tostring.py b/slixmpp/xmlstream/tostring.py
index 041346cb..6726bf1e 100644
--- a/slixmpp/xmlstream/tostring.py
+++ b/slixmpp/xmlstream/tostring.py
@@ -174,7 +174,7 @@ def _get_highlight():
             def __init__(self, string):
                 self.string = string
             def __str__(self):
-                return highlight(str(self.string).strip(), LEXER, FORMATTER)
+                return highlight(str(self.string), LEXER, FORMATTER).strip()
 
         return Highlighter
     except ImportError: