diff --git a/django/core/serializers/json.py b/django/core/serializers/json.py
index c2407d2a71..7b570f36d8 100644
--- a/django/core/serializers/json.py
+++ b/django/core/serializers/json.py
@@ -18,7 +18,9 @@ class Serializer(PythonSerializer):
     internal_use_only = False
 
     def end_serialization(self):
-        self.options.update({'use_decimal': False}) # Use JS strings to represent Python Decimal instances (ticket #16850)
+        if simplejson.__version__.split('.') >= ['2', '1', '3']:
+            # Use JS strings to represent Python Decimal instances (ticket #16850)
+            self.options.update({'use_decimal': False})
         simplejson.dump(self.objects, self.stream, cls=DjangoJSONEncoder, **self.options)
 
     def getvalue(self):