diff --git a/django/core/serializers/json.py b/django/core/serializers/json.py
index b07aa33..01d44e6 100644
--- a/django/core/serializers/json.py
+++ b/django/core/serializers/json.py
@@ -24,6 +24,11 @@ class Serializer(PythonSerializer):
     internal_use_only = False
 
     def start_serialization(self):
+        if self.options.get('indent'):
+            # The default is (', ', ': '). To eliminate useless whitespaces
+            # after the comma at the end of each line, the representation is
+            # changed to (',', ': ') only if indent is used.
+            self.options['separators'] = (',', ': ')
         if json.__version__.split('.') >= ['2', '1', '3']:
             # Use JS strings to represent Python Decimal instances (ticket #16850)
             self.options.update({'use_decimal': False})
@@ -37,8 +42,6 @@ class Serializer(PythonSerializer):
         if self.options.get("indent"):
             self.stream.write("\n")
         self.stream.write("]")
-        if self.options.get("indent"):
-            self.stream.write("\n")
 
     def end_object(self, obj):
         # self._current has the field data
diff --git a/tests/serializers/tests.py b/tests/serializers/tests.py
index 07c220c..4ddbc5c 100644
--- a/tests/serializers/tests.py
+++ b/tests/serializers/tests.py
@@ -392,6 +392,32 @@ class JsonSerializerTestCase(SerializersTestBase, TestCase):
                 ret_list.append(obj_dict["fields"][field_name])
         return ret_list
 
+
+class TestJsonSerializerIndentation(TestCase):
+    def test_indentation_whitespace(self):
+        from django.core.serializers.json import Serializer
+        Score.objects.create(score=5.0)
+        Score.objects.create(score=6.0)
+        qset = Score.objects.all()
+
+        s = Serializer()
+        self.assertEqual(s.serialize(qset, indent=2),"""[
+{
+  "pk": 1,
+  "model": "serializers.score",
+  "fields": {
+    "score": 5.0
+  }
+},
+{
+  "pk": 2,
+  "model": "serializers.score",
+  "fields": {
+    "score": 6.0
+  }
+}
+]""")
+
 class JsonSerializerTransactionTestCase(SerializersTransactionTestBase, TransactionTestCase):
     serializer_name = "json"
     fwd_ref_str = """[