1 files changed, 5 insertions, 8 deletions
diff --git a/sphinx/util/jsonimpl.py b/sphinx/util/jsonimpl.py
index d5a4f8293..ecb0b791a 100644
--- a/sphinx/util/jsonimpl.py
+++ b/sphinx/util/jsonimpl.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 """
     sphinx.util.jsonimpl
     ~~~~~~~~~~~~~~~~~~~~
@@ -10,9 +9,7 @@
 """
 
 import json
-
-from six import text_type
-from six.moves import UserString
+from collections import UserString
 
 if False:
     # For type annotation
@@ -22,10 +19,10 @@ if False:
 class SphinxJSONEncoder(json.JSONEncoder):
     """JSONEncoder subclass that forces translation proxies."""
     def default(self, obj):
-        # type: (Any) -> unicode
+        # type: (Any) -> str
         if isinstance(obj, UserString):
-            return text_type(obj)
-        return json.JSONEncoder.default(self, obj)
+            return str(obj)
+        return super().default(obj)
 
 
 def dump(obj, fp, *args, **kwds):
@@ -35,7 +32,7 @@ def dump(obj, fp, *args, **kwds):
 
 
 def dumps(obj, *args, **kwds):
-    # type: (Any, Any, Any) -> unicode
+    # type: (Any, Any, Any) -> str
     kwds['cls'] = SphinxJSONEncoder
     return json.dumps(obj, *args, **kwds)