diff --git a/src/calibre/ebooks/conversion/utils.py b/src/calibre/ebooks/conversion/utils.py
index b37cd4b869..d0dc81405b 100644
--- a/src/calibre/ebooks/conversion/utils.py
+++ b/src/calibre/ebooks/conversion/utils.py
@@ -580,10 +580,10 @@ class HeuristicProcessor(object):
             if blanks_count >= 1:
                 html = self.merge_blanks(html, blanks_count)
             # Center separator lines, use a bit larger margin in this case
-            html = re.sub(u'<(?P<outer>p|div)[^>]*>\s*(<(?P<inner1>font|span|[ibu])[^>]*>)?\s*(<(?P<inner2>font|span|[ibu])[^>]*>)?\s*(<(?P<inner3>font|span|[ibu])[^>]*>)?\s*(?P<break>([*#•=✦]+\s*)+)\s*(</(?P=inner3)>)?\s*(</(?P=inner2)>)?\s*(</(?P=inner1)>)?\s*</(?P=outer)>', '<p style="text-align:center; margin-top:.65em; margin-bottom:.65em; page-break-before:avoid">' + '\g<break>' + '</p>', html)
+            html = re.sub(u'<(?P<outer>p|div)[^>]*>\s*(<(?P<inner1>font|span|[ibu])[^>]*>)?\s*(<(?P<inner2>font|span|[ibu])[^>]*>)?\s*(<(?P<inner3>font|span|[ibu])[^>]*>)?\s*(?![\w\'\"])(?P<break>((?P<breakchar>(?!\s)\W)\s*(?P=breakchar)?)+)\s*(</(?P=inner3)>)?\s*(</(?P=inner2)>)?\s*(</(?P=inner1)>)?\s*</(?P=outer)>', '<p style="text-align:center; margin-top:.65em; margin-bottom:.65em; page-break-before:avoid">' + '\g<break>' + '</p>', html)
             #html = re.sub('<p\s+class="softbreak"[^>]*>\s*</p>', '<div id="softbreak" style="margin-left: 45%; margin-right: 45%; margin-top:1.5em; margin-bottom:1.5em"><hr style="height: 3px; background:#505050" /></div>', html)
 
         if self.deleted_nbsps:
             # put back non-breaking spaces in empty paragraphs so they render correctly
             html = self.anyblank.sub('\n'+r'\g<openline>'+u'\u00a0'+r'\g<closeline>', html)
-        return html
+        return html
\ No newline at end of file