diff --git a/src/calibre/ebooks/lit/oeb.py b/src/calibre/ebooks/lit/oeb.py
index 8ef7f41add..02a4996dd0 100644
--- a/src/calibre/ebooks/lit/oeb.py
+++ b/src/calibre/ebooks/lit/oeb.py
@@ -524,8 +524,6 @@ class TOC(object):
 
 class OEBBook(object):
     def __init__(self, opfpath=None, container=None):
-        if not opfpath:
-            opfpath = 'content.opf'
         if not container:
             container = DirContainer(os.path.dirname(opfpath))
             opfpath = os.path.basename(opfpath)