diff -r 2c27093fd11f Doc/library/json.rst
--- a/Doc/library/json.rst	Mon Apr 30 06:20:37 2012 +0200
+++ b/Doc/library/json.rst	Mon Apr 30 08:34:13 2012 +0200
@@ -112,7 +112,7 @@ Using json.tool from the shell to valida
 Basic Usage
 -----------
 
-.. function:: dump(obj, fp, skipkeys=False, ensure_ascii=True, check_circular=True, allow_nan=True, cls=None, indent=None, separators=None, default=None, **kw)
+.. function:: dump(obj, fp, skipkeys=False, ensure_ascii=True, check_circular=True, allow_nan=True, cls=None, indent=None, separators=None, default=None, sort_keys=False, **kw)
 
    Serialize *obj* as a JSON formatted stream to *fp* (a ``.write()``-supporting
    file-like object).
@@ -156,8 +156,11 @@ Basic Usage
    :meth:`default` method to serialize additional types), specify it with the
    *cls* kwarg; otherwise :class:`JSONEncoder` is used.
 
+   If *sort_keys* is true, then the output of dictionaries will be sorted by key;
+   this is useful for regression tests to ensure that JSON serializations can be
+   compared on a day-to-day basis.
 
-.. function:: dumps(obj, skipkeys=False, ensure_ascii=True, check_circular=True, allow_nan=True, cls=None, indent=None, separators=None, default=None, **kw)
+.. function:: dumps(obj, skipkeys=False, ensure_ascii=True, check_circular=True, allow_nan=True, cls=None, indent=None, separators=None, default=None, sort_keys=False, **kw)
 
    Serialize *obj* to a JSON formatted :class:`str`.  The arguments have the
    same meaning as in :func:`dump`.
diff -r 2c27093fd11f Lib/json/__init__.py
--- a/Lib/json/__init__.py	Mon Apr 30 06:20:37 2012 +0200
+++ b/Lib/json/__init__.py	Mon Apr 30 08:34:13 2012 +0200
@@ -122,7 +122,7 @@ from .encoder import JSONEncoder
 
 def dump(obj, fp, skipkeys=False, ensure_ascii=True, check_circular=True,
         allow_nan=True, cls=None, indent=None, separators=None,
-        default=None, **kw):
+        default=None, sort_keys=False, **kw):
     """Serialize ``obj`` as a JSON formatted stream to ``fp`` (a
     ``.write()``-supporting file-like object).
 
@@ -159,7 +159,11 @@ def dump(obj, fp, skipkeys=False, ensure
     ``.default()`` method to serialize additional types), specify it with
     the ``cls`` kwarg; otherwise ``JSONEncoder`` is used.
 
+    If sort_keys is true, then the output of dictionaries will be
+    sorted by key; this is useful for regression tests to ensure
+    that JSON serializations can be compared on a day-to-day basis.
     """
+    kw['sort_keys'] = sort_keys
     # cached encoder
     if (not skipkeys and ensure_ascii and
         check_circular and allow_nan and
@@ -181,7 +185,7 @@ def dump(obj, fp, skipkeys=False, ensure
 
 def dumps(obj, skipkeys=False, ensure_ascii=True, check_circular=True,
         allow_nan=True, cls=None, indent=None, separators=None,
-        default=None, **kw):
+        default=None, sort_keys=False, **kw):
     """Serialize ``obj`` to a JSON formatted ``str``.
 
     If ``skipkeys`` is false then ``dict`` keys that are not basic types
@@ -217,7 +221,11 @@ def dumps(obj, skipkeys=False, ensure_as
     ``.default()`` method to serialize additional types), specify it with
     the ``cls`` kwarg; otherwise ``JSONEncoder`` is used.
 
+    If sort_keys is true, then the output of dictionaries will be
+    sorted by key; this is useful for regression tests to ensure
+    that JSON serializations can be compared on a day-to-day basis.
     """
+    kw['sort_keys'] = sort_keys
     # cached encoder
     if (not skipkeys and ensure_ascii and
         check_circular and allow_nan and