diff --git a/src/calibre/ebooks/conversion/preprocess.py b/src/calibre/ebooks/conversion/preprocess.py
index 264b933047..840eff4c12 100644
--- a/src/calibre/ebooks/conversion/preprocess.py
+++ b/src/calibre/ebooks/conversion/preprocess.py
@@ -212,13 +212,13 @@ class Dehyphenator(object):
         self.html = html
         self.format = format
         if format == 'html':
-            intextmatch = re.compile(u'(?<=.{%i})(?P<firstpart>[^“"\s>]+)-\s*(?=<)(?P<wraptags></span>\s*(</[iubp]>\s*<[iubp][^>]*>\s*)?<span[^>]*>|</[iubp]>\s*<[iubp][^>]*>)?\s*(?P<secondpart>[\w\d]+)' % length)
+            intextmatch = re.compile(u'(?<=.{%i})(?P<firstpart>[^\[\]\\\^\$\.\|\?\*\+\(\)“"\s>]+)-\s*(?=<)(?P<wraptags></span>\s*(</[iubp]>\s*<[iubp][^>]*>\s*)?<span[^>]*>|</[iubp]>\s*<[iubp][^>]*>)?\s*(?P<secondpart>[\w\d]+)' % length)
         elif format == 'pdf':
-            intextmatch = re.compile(u'(?<=.{%i})(?P<firstpart>[^“"\s>]+)-\s*(?P<wraptags><p>|</[iub]>\s*<p>\s*<[iub]>)\s*(?P<secondpart>[\w\d]+)'% length)
+            intextmatch = re.compile(u'(?<=.{%i})(?P<firstpart>[^\[\]\\\^\$\.\|\?\*\+\(\)“"\s>]+)-\s*(?P<wraptags><p>|</[iub]>\s*<p>\s*<[iub]>)\s*(?P<secondpart>[\w\d]+)'% length)
         elif format == 'individual_words':
-            intextmatch = re.compile('>[^<]*\b(?P<firstpart>[^"\s>]+)-(?P<secondpart)\w+)\b[^<]*<') # for later, not called anywhere yet
+            intextmatch = re.compile(u'>[^<]*\b(?P<firstpart>[^\[\]\\\^\$\.\|\?\*\+\(\)"\s>]+)-(?P<secondpart)\w+)\b[^<]*<') # for later, not called anywhere yet
         elif format == 'html_cleanup':
-            intextmatch = re.compile(u'(?P<firstpart>[^“"\s>]+)-\s*(?=<)(?P<wraptags></span>\s*(</[iubp]>\s*<[iubp][^>]*>\s*)?<span[^>]*>|</[iubp]>\s*<[iubp][^>]*>)?\s*(?P<secondpart>[\w\d]+)')
+            intextmatch = re.compile(u'(?P<firstpart>[^\[\]\\\^\$\.\|\?\*\+\(\)“"\s>]+)-\s*(?=<)(?P<wraptags></span>\s*(</[iubp]>\s*<[iubp][^>]*>\s*)?<span[^>]*>|</[iubp]>\s*<[iubp][^>]*>)?\s*(?P<secondpart>[\w\d]+)')
 
         html = intextmatch.sub(self.dehyphenate, html)
         return html