diff -r 44ebac378e51 Lib/multiprocessing/forking.py
--- a/Lib/multiprocessing/forking.py	Wed Feb 27 10:04:23 2013 -0800
+++ b/Lib/multiprocessing/forking.py	Wed Feb 27 14:55:50 2013 -0500
@@ -438,7 +438,7 @@
         elif main_name != 'ipython':
             # Main modules not actually called __main__.py may
             # contain additional code that should still be executed
-            import imp
+            import importlib
 
             if main_path is None:
                 dirs = None
@@ -449,16 +449,12 @@
 
             assert main_name not in sys.modules, main_name
             sys.modules.pop('__mp_main__', None)
-            file, path_name, etc = imp.find_module(main_name, dirs)
-            try:
-                # We should not do 'imp.load_module("__main__", ...)'
-                # since that would execute 'if __name__ == "__main__"'
-                # clauses, potentially causing a psuedo fork bomb.
-                main_module = imp.load_module(
-                    '__mp_main__', file, path_name, etc
-                    )
-            finally:
-                if file:
-                    file.close()
+            loader = importlib.find_loader(main_name, dirs)
+            # We should not do 'loader.load_module("__main__", ...)'
+            # since that would execute 'if __name__ == "__main__"'
+            # clauses, potentially causing a psuedo fork bomb.
+            loader.load_module(main_name)
+            # Old loaders may not return the module from load_module().
+            main_module = sys.modules[main_name]
 
             sys.modules['__main__'] = sys.modules['__mp_main__'] = main_module