diff --git a/zulip/README.md b/zulip/README.md
index 91935b6..cffd204 100644
--- a/zulip/README.md
+++ b/zulip/README.md
@@ -4,7 +4,6 @@ The [Zulip API](https://zulipchat.com/api) Python bindings require the
 following Python libraries:
 
 * requests (version >= 0.12.1)
-* simplejson
 * six
 * typing (version >= 3.5.2.2)
 
diff --git a/zulip/integrations/zephyr/sync-public-streams b/zulip/integrations/zephyr/sync-public-streams
index 0971dcd..26441db 100755
--- a/zulip/integrations/zephyr/sync-public-streams
+++ b/zulip/integrations/zephyr/sync-public-streams
@@ -4,7 +4,7 @@ import os
 import logging
 import optparse
 import time
-import simplejson
+import json
 import subprocess
 import unicodedata
 
@@ -68,7 +68,7 @@ if __name__ == "__main__":
             continue
 
         f = open("/home/zulip/public_streams.tmp", "w")
-        f.write(simplejson.dumps(list(public_streams)) + "\n")
+        f.write(json.dumps(list(public_streams)) + "\n")
         f.close()
 
         subprocess.call(["mv", "/home/zulip/public_streams.tmp", "/home/zulip/public_streams"])
diff --git a/zulip/integrations/zephyr/zephyr_mirror_backend.py b/zulip/integrations/zephyr/zephyr_mirror_backend.py
index 785ca93..8162aab 100755
--- a/zulip/integrations/zephyr/zephyr_mirror_backend.py
+++ b/zulip/integrations/zephyr/zephyr_mirror_backend.py
@@ -27,10 +27,7 @@ from types import FrameType
 import sys
 from six.moves import map
 from six.moves import range
-try:
-    import simplejson
-except ImportError:
-    import json as simplejson  # type: ignore
+import json
 import re
 import time
 import subprocess
@@ -205,7 +202,7 @@ def update_subscriptions():
     # type: () -> None
     try:
         f = open(options.stream_file_path, "r")
-        public_streams = simplejson.loads(f.read())
+        public_streams = json.loads(f.read())
         f.close()
     except Exception:
         logger.exception("Error reading public streams:")
@@ -447,7 +444,7 @@ def process_notice(notice, log):
     logger.info("Received a message on %s/%s from %s..." %
                 (zephyr_class, notice.instance, notice.sender))
     if log is not None:
-        log.write(simplejson.dumps(zeph) + '\n')
+        log.write(json.dumps(zeph) + '\n')
         log.flush()
 
     if os.fork() == 0:
@@ -552,7 +549,7 @@ def zephyr_to_zulip(options):
         with open(options.logs_to_resend, 'r') as log:
             for ln in log:
                 try:
-                    zeph = simplejson.loads(ln)
+                    zeph = json.loads(ln)
                     # New messages added to the log shouldn't have any
                     # elements of type str (they should already all be
                     # unicode), but older messages in the log are
diff --git a/zulip/setup.py b/zulip/setup.py
index 42f179b..4122a21 100755
--- a/zulip/setup.py
+++ b/zulip/setup.py
@@ -65,7 +65,6 @@ package_info = dict(
 
 setuptools_info = dict(
     install_requires=['requests>=0.12.1',
-                      'simplejson',
                       'six',
                       'typing>=3.5.2.2',
                       ],
@@ -80,11 +79,6 @@ except ImportError:
     from distutils.core import setup
     from distutils.version import LooseVersion
     # Manual dependency check
-    try:
-        import simplejson
-    except ImportError:
-        print("simplejson is not installed", file=sys.stderr)
-        sys.exit(1)
     try:
         import requests
         assert(LooseVersion(requests.__version__) >= LooseVersion('0.12.1'))
diff --git a/zulip/zulip/__init__.py b/zulip/zulip/__init__.py
index e6bcb96..be474e5 100644
--- a/zulip/zulip/__init__.py
+++ b/zulip/zulip/__init__.py
@@ -23,7 +23,7 @@
 from __future__ import print_function
 from __future__ import absolute_import
 from __future__ import division
-import simplejson
+import json
 import requests
 import time
 import traceback
@@ -434,7 +434,7 @@ class Client(object):
             if isinstance(val, str) or isinstance(val, Text):
                 request[key] = val
             else:
-                request[key] = simplejson.dumps(val)
+                request[key] = json.dumps(val)
 
         for f in files:
             req_files.append((f.name, f))
@@ -459,7 +459,7 @@ class Client(object):
                 else:
                     sys.stdout.write(".")
                 sys.stdout.flush()
-            query_state["request"]["dont_block"] = simplejson.dumps(True)
+            query_state["request"]["dont_block"] = json.dumps(True)
             time.sleep(1)
             query_state["failures"] += 1
             return True