diff --git a/src/calibre/library/catalogs/epub_mobi_builder.py b/src/calibre/library/catalogs/epub_mobi_builder.py
index baa28d5974..1d806df3b2 100644
--- a/src/calibre/library/catalogs/epub_mobi_builder.py
+++ b/src/calibre/library/catalogs/epub_mobi_builder.py
@@ -644,7 +644,7 @@ class CatalogBuilder(object):
                 c = item
 
             ordnum, ordlen = collation_order(c)
-            if isosx and platform.mac_ver()[0] < '10.7':
+            if isosx and platform.mac_ver()[0] < '10.8':
                 # Hackhackhackhackhack
                 # icu returns bogus results with curly apostrophes, maybe others under OS X 10.6.x
                 # When we see the magic combo of 0/-1 for ordnum/ordlen, special case the logic