diff --git a/src/calibre/ebooks/mobi/writer8/skeleton.py b/src/calibre/ebooks/mobi/writer8/skeleton.py
index ae8fdf364c..2c3562e87b 100644
--- a/src/calibre/ebooks/mobi/writer8/skeleton.py
+++ b/src/calibre/ebooks/mobi/writer8/skeleton.py
@@ -10,6 +10,7 @@ __docformat__ = 'restructuredtext en'
 import re
 from collections import namedtuple
 from functools import partial
+from xml.sax.saxutils import escape
 
 from lxml import etree
 
@@ -289,6 +290,7 @@ class Chunker(object):
         self.chunk_selector = ('S', aid)
 
     def chunk_up_text(self, text):
+        text = escape(text)
         text = text.encode('utf-8')
         ans = []