diff --git a/src/calibre/utils/fonts/sfnt/container.py b/src/calibre/utils/fonts/sfnt/container.py
index a634b1a80e..cf207d0bd1 100644
--- a/src/calibre/utils/fonts/sfnt/container.py
+++ b/src/calibre/utils/fonts/sfnt/container.py
@@ -58,16 +58,21 @@ class Sfnt(object):
         del self.tables[key]
 
     def __iter__(self):
-        '''Iterate over the table tags in optimal order as per
-        http://partners.adobe.com/public/developer/opentype/index_recs.html'''
-        keys = list(self.tables.keys())
-        order = {x:i for i, x in enumerate((b'head', b'hhea', b'maxp', b'OS/2',
-            b'hmtx', b'LTSH', b'VDMX', b'hdmx', b'cmap', b'fpgm', b'prep',
-            b'cvt ', b'loca', b'glyf', b'CFF ', b'kern', b'name', b'post',
-            b'gasp', b'PCLT', b'DSIG'))}
-        keys.sort(key=lambda x:order.get(x, 1000))
-        for x in keys:
+        '''Iterate over the table tags in order.'''
+        for x in sorted(self.tables.iterkeys()):
             yield x
+        # Although the optimal order is not alphabetical, the OTF spec says
+        # they should be alphabetical, so we stick with that. See
+        # http://partners.adobe.com/public/developer/opentype/index_recs.html
+        # for optimal order.
+        # keys = list(self.tables.iterkeys())
+        # order = {x:i for i, x in enumerate((b'head', b'hhea', b'maxp', b'OS/2',
+        #     b'hmtx', b'LTSH', b'VDMX', b'hdmx', b'cmap', b'fpgm', b'prep',
+        #     b'cvt ', b'loca', b'glyf', b'CFF ', b'kern', b'name', b'post',
+        #     b'gasp', b'PCLT', b'DSIG'))}
+        # keys.sort(key=lambda x:order.get(x, 1000))
+        # for x in keys:
+        #     yield x
 
     def pop(self, key, default=None):
         return self.tables.pop(key, default)