diff --git a/src/calibre/ebooks/epub/iterator.py b/src/calibre/ebooks/epub/iterator.py
index d47630a970..08c275e81f 100644
--- a/src/calibre/ebooks/epub/iterator.py
+++ b/src/calibre/ebooks/epub/iterator.py
@@ -170,7 +170,10 @@ class EbookIterator(object):
         dat = self.serialize_bookmarks(bookmarks)
         if os.path.splitext(self.pathtoebook)[1].lower() == '.epub' and \
             os.access(self.pathtoebook, os.R_OK):
-            zf = open(self.pathtoebook, 'r+b')
+            try:
+                zf = open(self.pathtoebook, 'r+b')
+            except IOError:
+                return
             zipf = ZipFile(zf, mode='a')
             for name in zipf.namelist():
                 if name == 'META-INF/calibre_bookmarks.txt':