diff -r ede0a342ed7e Lib/inspect.py
--- a/Lib/inspect.py	Thu Jan 23 16:49:22 2014 +0200
+++ b/Lib/inspect.py	Thu Jan 23 15:15:30 2014 -0500
@@ -516,9 +516,10 @@
             return object.__file__
         raise TypeError('{!r} is a built-in module'.format(object))
     if isclass(object):
-        object = sys.modules.get(object.__module__)
-        if hasattr(object, '__file__'):
-            return object.__file__
+        if hasattr(object, '__module__'):
+            object = sys.modules.get(object.__module__)
+            if hasattr(object, '__file__'):
+                return object.__file__
         raise TypeError('{!r} is a built-in class'.format(object))
     if ismethod(object):
         object = object.__func__