1 files changed, 10 insertions, 20 deletions
diff --git a/sphinx/util/jsonimpl.py b/sphinx/util/jsonimpl.py
index 8c51f4416..1d296b6b7 100644
--- a/sphinx/util/jsonimpl.py
+++ b/sphinx/util/jsonimpl.py
@@ -9,28 +9,18 @@
     :license: BSD, see LICENSE for details.
 """
 
-import UserString
-
-try:
-    import json
-    # json-py's json module has no JSONEncoder; this will raise AttributeError
-    # if json-py is imported instead of the built-in json module
-    JSONEncoder = json.JSONEncoder
-except (ImportError, AttributeError):
-    try:
-        import simplejson as json
-        JSONEncoder = json.JSONEncoder
-    except ImportError:
-        json = None
-        JSONEncoder = object
-
-
-class SphinxJSONEncoder(JSONEncoder):
+import json
+
+from six import text_type
+from six.moves import UserString
+
+
+class SphinxJSONEncoder(json.JSONEncoder):
     """JSONEncoder subclass that forces translation proxies."""
     def default(self, obj):
-        if isinstance(obj, UserString.UserString):
-            return unicode(obj)
-        return JSONEncoder.default(self, obj)
+        if isinstance(obj, UserString):
+            return text_type(obj)
+        return json.JSONEncoder.default(self, obj)
 
 
 def dump(obj, fp, *args, **kwds):