diff -r a5e621c8dd44 Lib/imp.py
--- a/Lib/imp.py	Wed May 30 22:17:30 2012 +1000
+++ b/Lib/imp.py	Fri Jun 01 12:04:48 2012 +0100
@@ -147,7 +147,7 @@
                 break
         else:
             raise ValueError('{!r} is not a package'.format(path))
-    return _bootstrap.SourceFileLoader(name, path).load_module(name)
+    return _bootstrap.SourceFileLoader(name, path, True).load_module(name)
 
 
 # XXX deprecate
diff -r a5e621c8dd44 Lib/importlib/_bootstrap.py
--- a/Lib/importlib/_bootstrap.py	Wed May 30 22:17:30 2012 +1000
+++ b/Lib/importlib/_bootstrap.py	Fri Jun 01 12:04:48 2012 +0100
@@ -762,11 +762,16 @@
     """Base file loader class which implements the loader protocol methods that
     require file system usage."""
 
-    def __init__(self, fullname, path):
+    def __init__(self, fullname, path, is_package=False):
         """Cache the module name and the path to the file found by the
         finder."""
         self.name = fullname
         self.path = path
+        self._is_package = is_package
+
+    @_check_name
+    def is_package(self, fullname):
+        return self._is_package
 
     @_check_name
     def load_module(self, fullname):
@@ -1111,7 +1116,7 @@
                     init_filename = '__init__' + suffix
                     full_path = _path_join(base_path, init_filename)
                     if _path_isfile(full_path):
-                        return (loader(fullname, full_path), [base_path])
+                        return (loader(fullname, full_path, True), [base_path])
                 else:
                     # A namespace package, return the path
                     return (None, [base_path])
diff -r a5e621c8dd44 Lib/importlib/test/source/test_file_loader.py
--- a/Lib/importlib/test/source/test_file_loader.py	Wed May 30 22:17:30 2012 +1000
+++ b/Lib/importlib/test/source/test_file_loader.py	Fri Jun 01 12:04:48 2012 +0100
@@ -73,7 +73,7 @@
     def test_package(self):
         with source_util.create_modules('_pkg.__init__') as mapping:
             loader = _bootstrap.SourceFileLoader('_pkg',
-                                                 mapping['_pkg.__init__'])
+                                            mapping['_pkg.__init__'], True)
             module = loader.load_module('_pkg')
             self.assertTrue('_pkg' in sys.modules)
             check = {'__name__': '_pkg', '__file__': mapping['_pkg.__init__'],
diff -r a5e621c8dd44 Python/importlib.h
Binary file Python/importlib.h has changed