diff --git a/src/calibre/ebooks/txt/processor.py b/src/calibre/ebooks/txt/processor.py
index 8d6139e1cf..ba41378deb 100644
--- a/src/calibre/ebooks/txt/processor.py
+++ b/src/calibre/ebooks/txt/processor.py
@@ -99,9 +99,7 @@ def convert_markdown(txt, title='', extensions=('footnotes', 'tables', 'toc')):
     from calibre.ebooks.conversion.plugins.txt_input import MD_EXTENSIONS
     from calibre.ebooks.markdown import Markdown
     extensions = [x.lower() for x in extensions if x.lower() in MD_EXTENSIONS]
-    md = Markdown(
-          extensions,
-          safe_mode=False)
+    md = Markdown(extensions=extensions, safe_mode=False)
     return HTML_TEMPLATE % (title, md.convert(txt))
 
 def convert_textile(txt, title=''):