diff --git a/src/fix.py b/src/fix.py
index 4a3a39f83..cc4bd7eb0 100644
--- a/src/fix.py
+++ b/src/fix.py
@@ -213,8 +213,11 @@ if not hasattr(Exception, '_original__init__'):
         self._original__init__(*args, **kwargs)
     Exception.__init__ = __init__
 
+import atexit
+def _replace_original__init__():
+    Exception.__init__ = Exception._original__init__
+atexit.register(_replace_original__init__)g = globals()
 
-g = globals()
 for name in exported:
     __builtins__[name] = g[name]