diff --git a/src/calibre/gui2/viewer/documentview.py b/src/calibre/gui2/viewer/documentview.py
index 6a263459e6..06e501351a 100644
--- a/src/calibre/gui2/viewer/documentview.py
+++ b/src/calibre/gui2/viewer/documentview.py
@@ -684,7 +684,7 @@ class DocumentView(QWebView):  # {{{
                 menu.addAction(ac.icon(), '%s [%s]' % (unicode(ac.text()), ','.join(self.shortcuts.get_shortcuts(sc))), ac.trigger)
 
         if from_touch and self.manager is not None:
-            word = unicode(mf.evaluateJavaScript('window.calibre_utils.word_at_point(%f, %f)' % (ev.pos().x(), ev.pos().y())).toString())
+            word = unicode(mf.evaluateJavaScript('window.calibre_utils.word_at_point(%f, %f)' % (ev.pos().x(), ev.pos().y())) or '')
             if word:
                 menu.addAction(self.dictionary_action.icon(), _('Lookup %s in the dictionary') % word, partial(self.manager.lookup, word))
                 menu.addAction(self.search_online_action.icon(), _('Search for %s online') % word, partial(self.do_search_online, word))