From 0b92b956372e5531b232790333b21961bcec1965 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Tue, 3 Feb 2015 09:39:58 +0530
Subject: [PATCH] ...

---
 src/calibre/ebooks/tweak.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/calibre/ebooks/tweak.py b/src/calibre/ebooks/tweak.py
index 58653c012c..16301607a5 100644
--- a/src/calibre/ebooks/tweak.py
+++ b/src/calibre/ebooks/tweak.py
@@ -88,7 +88,7 @@ def tweak(ebook_file):
     fmt = ebook_file.rpartition('.')[-1].lower()
     exploder, rebuilder = get_tools(fmt)
     if exploder is None:
-        prints('Cannot tweak %s files. Supported formats are: EPUB, HTMLZ, AZW3, MOBI'
+        prints('Cannot tweak %s files. Supported formats are: EPUB, HTMLZ, AZW3, MOBI' % fmt.upper()
                 , file=sys.stderr)
         raise SystemExit(1)