Index: Lib/cmd.py
===================================================================
--- Lib/cmd.py	(revision 72551)
+++ Lib/cmd.py	(working copy)
@@ -293,7 +293,10 @@
         return names
 
     def complete_help(self, *args):
-        return self.completenames(*args)
+        commands = set(self.completenames(*args))
+        topics = set([a[5:] for a in self.get_names()
+                      if a.startswith('help_'+text)])
+        return list(commands.union(topics))
 
     def do_help(self, arg):
         if arg: