diff --git a/setup.py b/setup.py
index add71ba..05e1133 100644
--- a/setup.py
+++ b/setup.py
@@ -1233,11 +1233,11 @@
                 bz2_extra_link_args = ('-Wl,-search_paths_first',)
             else:
                 bz2_extra_link_args = ()
-            exts.append( Extension('bz2', ['bz2module.c'],
+            exts.append( Extension('_bz2', ['_bz2module.c'],
                                    libraries = ['bz2'],
                                    extra_link_args = bz2_extra_link_args) )
         else:
-            missing.append('bz2')
+            missing.append('_bz2')
 
         # Interface to the Expat XML parser
         #