diff --git a/src/calibre/ebooks/mobi/writer8/toc.py b/src/calibre/ebooks/mobi/writer8/toc.py
index ec3a3cdd0c..74b5b9acab 100644
--- a/src/calibre/ebooks/mobi/writer8/toc.py
+++ b/src/calibre/ebooks/mobi/writer8/toc.py
@@ -60,7 +60,8 @@ class TOCAdder(object):
             else:
                 oeb.guide.remove('toc')
 
-        if not self.has_toc or 'toc' in oeb.guide or opts.no_inline_toc:
+        if (not self.has_toc or 'toc' in oeb.guide or opts.no_inline_toc or
+            getattr(opts, 'mobi_passthrough', False)):
             return
 
         self.log('\tGenerating in-line ToC')