Index: Doc/library/doctest.rst
===================================================================
--- Doc/library/doctest.rst	(revision 79554)
+++ Doc/library/doctest.rst	(working copy)
@@ -809,9 +809,9 @@
    * If *module_relative* is ``True`` (the default), then *filename* specifies an
      OS-independent module-relative path.  By default, this path is relative to the
      calling module's directory; but if the *package* argument is specified, then it
-     is relative to that package.  To ensure OS-independence, *filename* should use
-     ``/`` characters to separate path segments, and may not be an absolute path
-     (i.e., it may not begin with ``/``).
+     is relative to that package. To ensure that doctests run on every machine, a
+     :exc:`ValueError` is raised if an absolute path is used when *module_relative*
+     is set.
 
    * If *module_relative* is ``False``, then *filename* specifies an OS-specific
      path.  The path may be absolute or relative; relative paths are resolved with
Index: Lib/doctest.py
===================================================================
--- Lib/doctest.py	(revision 79554)
+++ Lib/doctest.py	(working copy)
@@ -355,21 +355,23 @@
         finally:
             sys.stdout = save_stdout
 
-# [XX] Normalize with respect to os.path.pardir?
 def _module_relative_path(module, path):
+    """Transform module-relative path to absolute"""
     if not inspect.ismodule(module):
         raise TypeError, 'Expected a module: %r' % module
-    if path.startswith('/'):
-        raise ValueError, 'Module-relative files may not have absolute paths'
+    if os.path.isabs(path):
+        raise ValueError('Absolute path specified as module-relative' +
+                         'path: ' + path)
+    path = os.path.normpath(path)
 
     # Find the base directory for the path.
     if hasattr(module, '__file__'):
         # A normal module/package
-        basedir = os.path.split(module.__file__)[0]
+        basedir = os.path.dirname(module.__file__)
     elif module.__name__ == '__main__':
         # An interactive session.
         if len(sys.argv)>0 and sys.argv[0] != '':
-            basedir = os.path.split(sys.argv[0])[0]
+            basedir = os.path.dirname(sys.argv[0])
         else:
             basedir = os.curdir
     else:
@@ -378,7 +380,7 @@
                          module + " (it has no __file__)")
 
     # Combine the base directory and the path.
-    return os.path.join(basedir, *(path.split('/')))
+    return os.path.join(basedir, path)
 
 ######################################################################
 ## 2. Example & DocTest
Index: Lib/test/test_doctest.py
===================================================================
--- Lib/test/test_doctest.py	(revision 79554)
+++ Lib/test/test_doctest.py	(working copy)
@@ -2201,11 +2201,11 @@
 optional `module_relative` parameter:
 
     >>> doctest.testfile('test_doctest.txt', globs=globs,
-    ...                  module_relative='test')
+    ...                  module_relative=True)
     TestResults(failed=0, attempted=2)
     >>> doctest.master = None  # Reset master.
 
-Verbosity can be increased with the optional `verbose` paremter:
+Verbosity can be increased with the optional `verbose` parameter:
 
     >>> doctest.testfile('test_doctest.txt', globs=globs, verbose=True)
     Trying: