Revert copy_reg -> copyreg rename.
diff --git a/Lib/re.py b/Lib/re.py
index 3f4f02c..1d9c987 100644
--- a/Lib/re.py
+++ b/Lib/re.py
@@ -278,12 +278,12 @@
 
 # register myself for pickling
 
-import copyreg
+import copy_reg
 
 def _pickle(p):
     return _compile, (p.pattern, p.flags)
 
-copyreg.pickle(_pattern_type, _pickle, _compile)
+copy_reg.pickle(_pattern_type, _pickle, _compile)
 
 # --------------------------------------------------------------------
 # experimental stuff (see python-dev discussions for details)