diff --git a/README.md b/README.md
index 64bff06..b04a073 100644
--- a/README.md
+++ b/README.md
@@ -53,7 +53,6 @@ You'll need these to run Supysonic:
 * [Flask](http://flask.pocoo.org/) >= 0.9
 * [PonyORM](https://ponyorm.com/)
 * [Python Imaging Library](https://github.com/python-pillow/Pillow)
-* [simplejson](https://simplejson.readthedocs.io/en/latest/)
 * [requests](http://docs.python-requests.org/)
 * [mutagen](https://mutagen.readthedocs.io/en/latest/)
 * [watchdog](https://github.com/gorakhargosh/watchdog)
diff --git a/requirements.txt b/requirements.txt
index d048741..df2c04e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,6 @@
 flask>=0.9
 pony
 Pillow
-simplejson
 requests>=1.0.0
 mutagen
 watchdog
diff --git a/supysonic/api/__init__.py b/supysonic/api/__init__.py
index d0104ad..d7f5abe 100644
--- a/supysonic/api/__init__.py
+++ b/supysonic/api/__init__.py
@@ -19,10 +19,9 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import binascii
-import simplejson
 import uuid
 
-from flask import request, current_app as app
+from flask import request, json, current_app as app
 from pony.orm import db_session, ObjectNotFound
 from xml.dom import minidom
 from xml.etree import ElementTree
@@ -163,11 +162,11 @@ class ResponseHelper:
             status = 'failed' if error else 'ok',
             version = version
         )
-        return simplejson.dumps({ 'subsonic-response': ret }, indent = True, encoding = 'utf-8')
+        return json.dumps({ 'subsonic-response': ret }, indent = True)
 
     @staticmethod
     def responsize_jsonp(ret, callback, error = False, version = "1.8.0"):
-        return "%s(%s)" % (callback, ResponseHelper.responsize_json(ret, error, version))
+        return '{}({})'.format(callback, ResponseHelper.responsize_json(ret, error, version))
 
     @staticmethod
     def responsize_xml(ret, error = False, version = "1.8.0"):
diff --git a/tests/api/test_api_setup.py b/tests/api/test_api_setup.py
index c68f342..989c1c7 100644
--- a/tests/api/test_api_setup.py
+++ b/tests/api/test_api_setup.py
@@ -11,7 +11,7 @@
 # Distributed under terms of the GNU AGPLv3 license.
 
 import base64
-import simplejson
+import flask.json
 
 from xml.etree import ElementTree
 
@@ -104,7 +104,7 @@ class ApiSetupTestCase(TestBase):
         rv = self.client.get('/rest/getLicense.view', query_string = args)
         self.assertEqual(rv.status_code, 200)
         self.assertEqual(rv.mimetype, 'application/json')
-        json = simplejson.loads(rv.data)
+        json = flask.json.loads(rv.data)
         self.assertIn('subsonic-response', json)
         self.assertEqual(json['subsonic-response']['status'], 'ok')
         self.assertIn('license', json['subsonic-response'])
@@ -112,7 +112,7 @@ class ApiSetupTestCase(TestBase):
         args.update({ 'f': 'jsonp' })
         rv = self.client.get('/rest/getLicense.view', query_string = args)
         self.assertEqual(rv.mimetype, 'application/javascript')
-        json = simplejson.loads(rv.data)
+        json = flask.json.loads(rv.data)
         self.assertIn('subsonic-response', json)
         self.assertEqual(json['subsonic-response']['status'], 'failed')
         self.assertEqual(json['subsonic-response']['error']['code'], 10)
@@ -123,7 +123,7 @@ class ApiSetupTestCase(TestBase):
         self.assertEqual(rv.mimetype, 'application/javascript')
         self.assertTrue(rv.data.startswith('dummy_cb({'))
         self.assertTrue(rv.data.endswith('})'))
-        json = simplejson.loads(rv.data[9:-1])
+        json = flask.json.loads(rv.data[9:-1])
         self.assertIn('subsonic-response', json)
         self.assertEqual(json['subsonic-response']['status'], 'ok')
         self.assertIn('license', json['subsonic-response'])
diff --git a/tests/api/test_response_helper.py b/tests/api/test_response_helper.py
index 4cee2ba..68f6dc5 100644
--- a/tests/api/test_response_helper.py
+++ b/tests/api/test_response_helper.py
@@ -10,8 +10,8 @@
 # Distributed under terms of the GNU AGPLv3 license.
 
 import unittest
+import flask.json
 
-import simplejson
 from xml.etree import ElementTree
 
 from supysonic.py23 import strtype
@@ -31,7 +31,7 @@ class ResponseHelperJsonTestCase(ResponseHelperBaseCase):
             raise TypeError('Invalid tested value, expecting a dict')
 
         json = self.helper.responsize_json(d, error)
-        return simplejson.loads(json)
+        return flask.json.loads(json)
 
     def process_and_extract(self, d, error = False):
         # Basically returns d with additional version and status
@@ -123,7 +123,7 @@ class ResponseHelperJsonpTestCase(ResponseHelperBaseCase):
         self.assertTrue(result.startswith('callback({'))
         self.assertTrue(result.endswith('})'))
 
-        json = simplejson.loads(result[9:-1])
+        json = flask.json.loads(result[9:-1])
         self.assertIn('subsonic-response', json)
 
 class ResponseHelperXMLTestCase(ResponseHelperBaseCase):