diff --git a/src/calibre/ebooks/mobi/writer2/serializer.py b/src/calibre/ebooks/mobi/writer2/serializer.py
index eeef720144..041a9922cb 100644
--- a/src/calibre/ebooks/mobi/writer2/serializer.py
+++ b/src/calibre/ebooks/mobi/writer2/serializer.py
@@ -212,7 +212,11 @@ class Serializer(object):
             if tocref.klass == "periodical":
                 buf.write('<div> <div height="1em"></div>')
             else:
-                buf.write('<div></div> <div> <h2 height="1em"><font size="+2"><b>'+tocref.title+'</b></font></h2> <div height="1em"></div>')
+                t = tocref.title
+                if isinstance(t, unicode):
+                    t = t.encode('utf-8')
+                buf.write('<div></div> <div> <h2 height="1em"><font size="+2"><b>'
+                        +t+'</b></font></h2> <div height="1em"></div>')
 
             buf.write('<ul>')
 
@@ -221,14 +225,17 @@ class Serializer(object):
                 itemhref = tocitem.href
                 if tocref.klass == 'periodical':
                     # This is a section node.
-                    # For periodical toca, the section urls are like r'feed_\d+/index.html'
+                    # For periodical tocs, the section urls are like r'feed_\d+/index.html'
                     # We dont want to point to the start of the first article
                     # so we change the href.
                     itemhref = re.sub(r'article_\d+/', '', itemhref)
                 self.href_offsets[itemhref].append(buf.tell())
                 buf.write('0000000000')
                 buf.write(' ><font size="+1" color="blue"><b><u>')
-                buf.write(tocitem.title)
+                t = tocitem.title
+                if isinstance(t, unicode):
+                    t = t.encode('utf-8')
+                buf.write(t)
                 buf.write('</u></b></font></a></li>')
 
             buf.write('</ul><div height="1em"></div></div><mbp:pagebreak />')