diff --git a/lib-python/2.7/compileall.py b/Lib/compileall.py
rename from lib-python/2.7/compileall.py
rename to Lib/compileall.py
--- a/lib-python/2.7/compileall.py
+++ b/Lib/compileall.py
@@ -86,7 +86,7 @@
                 try:
                     mtime = int(os.stat(fullname).st_mtime)
                     expect = struct.pack('<4sl', imp.get_magic(), mtime)
-                    cfile = fullname + (__debug__ and 'c' or 'o')
+                    cfile = fullname.replace('.py', '$py.class')
                     with open(cfile, 'rb') as chandle:
                         actual = chandle.read(8)
                     if expect == actual: