diff --git a/src/calibre/ebooks/mobi/reader.py b/src/calibre/ebooks/mobi/reader.py
index 093d8698bf..e664834260 100644
--- a/src/calibre/ebooks/mobi/reader.py
+++ b/src/calibre/ebooks/mobi/reader.py
@@ -245,7 +245,7 @@ class MetadataHeader(BookHeader):
class MobiReader(object):
PAGE_BREAK_PAT = re.compile(
- r'<\s*mbp:pagebreak((?:\s+[^/>]*){0,1})/{0,1}\s*>\s*(?:<\s*/{0,1}\s*mbp:pagebreak\s*/{0,1}\s*>)*',
+ r'<\s*/{0,1}\s*mbp:pagebreak((?:\s+[^/>]*){0,1})/{0,1}\s*>\s*(?:<\s*/{0,1}\s*mbp:pagebreak\s*/{0,1}\s*>)*',
re.IGNORECASE)
IMAGE_ATTRS = ('lowrecindex', 'recindex', 'hirecindex')
@@ -1077,6 +1077,9 @@ def test_mbp_regex():
'xxx':'xxx',
'xxx':' sdfxxx',
'':' ',
+ '':'',
+ '':' sdf',
+ 'xxx':'xxx',
}.iteritems():
ans = MobiReader.PAGE_BREAK_PAT.sub(r'\1', raw)
if ans != m: