Revert copy_reg -> copyreg rename.
diff --git a/Doc/library/modulefinder.rst b/Doc/library/modulefinder.rst
index 402f5db..a086206 100644
--- a/Doc/library/modulefinder.rst
+++ b/Doc/library/modulefinder.rst
@@ -97,7 +97,7 @@
 
     Loaded modules:
     _types:
-    copyreg:  _inverted_registry,_slotnames,__all__
+    copy_reg:  _inverted_registry,_slotnames,__all__
     sre_compile:  isstring,_sre,_optimize_unicode
     _sre:
     sre_constants:  REPEAT_ONE,makedict,AT_END_LINE