diff --git a/.travis.yml b/.travis.yml
index c01068d..67c2d20 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -29,4 +29,4 @@ script:
   - if [ $TRAVIS_PYTHON_VERSION != '2.6' ]; then
     flake8 --ignore=E501,E128 zerorpc bin;
     fi
-  - nosetests -v
+  - pytest -v
diff --git a/doc/protocol.md b/doc/protocol.md
index 37a6417..cfc83d2 100644
--- a/doc/protocol.md
+++ b/doc/protocol.md
@@ -207,7 +207,7 @@ exception is raised), we use the ERR event.
 	- Name of the error (it should be the exception class name, or another
 	  meaningful keyword).
 	- Human representation of the error (preferably in english).
-	- If possible a pretty printed traceback of the call stack when the error occured.
+	- If possible a pretty printed traceback of the call stack when the error occurred.
 
 > A future version of the protocol will probably add a structured version of the
 > traceback, allowing machine-to-machine stack walking and better cross-language
diff --git a/setup.py b/setup.py
index 610e68b..b07ebcb 100644
--- a/setup.py
+++ b/setup.py
@@ -64,8 +64,8 @@
     url='https://github.com/0rpc/zerorpc-python',
     packages=['zerorpc'],
     install_requires=requirements,
-    tests_require=['nose'],
-    test_suite='nose.collector',
+    tests_require=['pytest'],
+    test_suite='pytest.collector',
     zip_safe=False,
     entry_points={'console_scripts': ['zerorpc = zerorpc.cli:main']},
     license='MIT',
diff --git a/tests/test_buffered_channel.py b/tests/test_buffered_channel.py
index 76d0fe3..20b8173 100644
--- a/tests/test_buffered_channel.py
+++ b/tests/test_buffered_channel.py
@@ -27,7 +27,7 @@
 from __future__ import absolute_import
 from builtins import range
 
-from nose.tools import assert_raises
+import pytest
 import gevent
 import sys
 
@@ -61,9 +61,9 @@ def test_close_server_bufchan():
     print('CLOSE SERVER SOCKET!!!')
     server_bufchan.close()
     if sys.version_info < (2, 7):
-        assert_raises(zerorpc.LostRemote, client_bufchan.recv)
+        pytest.raises(zerorpc.LostRemote, client_bufchan.recv)
     else:
-        with assert_raises(zerorpc.LostRemote):
+        with pytest.raises(zerorpc.LostRemote):
             client_bufchan.recv()
     print('CLIENT LOST SERVER :)')
     client_bufchan.close()
@@ -96,9 +96,9 @@ def test_close_client_bufchan():
     print('CLOSE CLIENT SOCKET!!!')
     client_bufchan.close()
     if sys.version_info < (2, 7):
-        assert_raises(zerorpc.LostRemote, client_bufchan.recv)
+        pytest.raises(zerorpc.LostRemote, client_bufchan.recv)
     else:
-        with assert_raises(zerorpc.LostRemote):
+        with pytest.raises(zerorpc.LostRemote):
             client_bufchan.recv()
     print('SERVER LOST CLIENT :)')
     server_bufchan.close()
@@ -129,9 +129,9 @@ def test_heartbeat_can_open_channel_server_close():
     print('CLOSE SERVER SOCKET!!!')
     server_bufchan.close()
     if sys.version_info < (2, 7):
-        assert_raises(zerorpc.LostRemote, client_bufchan.recv)
+        pytest.raises(zerorpc.LostRemote, client_bufchan.recv)
     else:
-        with assert_raises(zerorpc.LostRemote):
+        with pytest.raises(zerorpc.LostRemote):
             client_bufchan.recv()
     print('CLIENT LOST SERVER :)')
     client_bufchan.close()
@@ -170,9 +170,9 @@ def server_fn():
     client_bufchan.close()
     client.close()
     if sys.version_info < (2, 7):
-        assert_raises(zerorpc.LostRemote, server_coro.get)
+        pytest.raises(zerorpc.LostRemote, server_coro.get)
     else:
-        with assert_raises(zerorpc.LostRemote):
+        with pytest.raises(zerorpc.LostRemote):
             server_coro.get()
     print('SERVER LOST CLIENT :)')
     server.close()
@@ -244,9 +244,9 @@ def client_do():
             assert list(event.args) == [x + x * x]
         client_bufchan.emit('add', (x, x * x))
         if sys.version_info < (2, 7):
-            assert_raises(zerorpc.LostRemote, client_bufchan.recv)
+            pytest.raises(zerorpc.LostRemote, client_bufchan.recv)
         else:
-            with assert_raises(zerorpc.LostRemote):
+            with pytest.raises(zerorpc.LostRemote):
                 client_bufchan.recv()
         client_bufchan.close()
 
@@ -308,9 +308,9 @@ def server_do():
             server_bufchan.emit('OK', (sum(event.args),))
 
         if sys.version_info < (2, 7):
-            assert_raises(zerorpc.LostRemote, server_bufchan.recv)
+            pytest.raises(zerorpc.LostRemote, server_bufchan.recv)
         else:
-            with assert_raises(zerorpc.LostRemote):
+            with pytest.raises(zerorpc.LostRemote):
                 server_bufchan.recv()
         server_bufchan.close()
 
@@ -343,9 +343,9 @@ def _do_with_assert_raises():
                     event = client_bufchan.recv(timeout=TIME_FACTOR * 3)
                     assert event.name == 'OK'
                     assert list(event.args) == [x]
-            assert_raises(zerorpc.TimeoutExpired, _do_with_assert_raises)
+            pytest.raises(zerorpc.TimeoutExpired, _do_with_assert_raises)
         else:
-            with assert_raises(zerorpc.TimeoutExpired):
+            with pytest.raises(zerorpc.TimeoutExpired):
                 for x in range(10):
                     client_bufchan.emit('sleep', (x,))
                     event = client_bufchan.recv(timeout=TIME_FACTOR * 3)
@@ -369,9 +369,9 @@ def _do_with_assert_raises():
                     assert event.name == 'sleep'
                     gevent.sleep(TIME_FACTOR * event.args[0])
                     server_bufchan.emit('OK', event.args)
-            assert_raises(zerorpc.LostRemote, _do_with_assert_raises)
+            pytest.raises(zerorpc.LostRemote, _do_with_assert_raises)
         else:
-            with assert_raises(zerorpc.LostRemote):
+            with pytest.raises(zerorpc.LostRemote):
                 for x in range(20):
                     event = server_bufchan.recv()
                     assert event.name == 'sleep'
@@ -422,9 +422,9 @@ def server_do():
             def _do_with_assert_raises():
                 for x in range(200):
                     server_bufchan.emit('coucou', x, timeout=0)  # will fail when x == 1
-            assert_raises(zerorpc.TimeoutExpired, _do_with_assert_raises)
+            pytest.raises(zerorpc.TimeoutExpired, _do_with_assert_raises)
         else:
-            with assert_raises(zerorpc.TimeoutExpired):
+            with pytest.raises(zerorpc.TimeoutExpired):
                 for x in range(200):
                     server_bufchan.emit('coucou', x, timeout=0)  # will fail when x == 1
         server_bufchan.emit('coucou', 1)  # block until receiver is ready
@@ -432,9 +432,9 @@ def _do_with_assert_raises():
             def _do_with_assert_raises():
                 for x in range(2, 200):
                     server_bufchan.emit('coucou', x, timeout=0)  # will fail when x == 100
-            assert_raises(zerorpc.TimeoutExpired, _do_with_assert_raises)
+            pytest.raises(zerorpc.TimeoutExpired, _do_with_assert_raises)
         else:
-            with assert_raises(zerorpc.TimeoutExpired):
+            with pytest.raises(zerorpc.TimeoutExpired):
                 for x in range(2, 200):
                     server_bufchan.emit('coucou', x, timeout=0)  # will fail when x == 100
         for x in range(read_cnt.value, 200):
diff --git a/tests/test_client_async.py b/tests/test_client_async.py
index 3acbd3b..ced4b1f 100644
--- a/tests/test_client_async.py
+++ b/tests/test_client_async.py
@@ -25,7 +25,7 @@
 
 from __future__ import print_function
 from __future__ import absolute_import
-from nose.tools import assert_raises
+import pytest
 import gevent
 import sys
 
@@ -53,14 +53,14 @@ def add(self, a, b):
     client = zerorpc.Client(timeout=TIME_FACTOR * 2)
     client.connect(endpoint)
 
-    async_result = client.add(1, 4, async=True)
+    async_result = client.add(1, 4, async_=True)
 
     if sys.version_info < (2, 7):
         def _do_with_assert_raises():
             print(async_result.get())
-        assert_raises(zerorpc.TimeoutExpired, _do_with_assert_raises)
+        pytest.raises(zerorpc.TimeoutExpired, _do_with_assert_raises)
     else:
-        with assert_raises(zerorpc.TimeoutExpired):
+        with pytest.raises(zerorpc.TimeoutExpired):
             print(async_result.get())
     client.close()
     srv.close()
@@ -84,8 +84,8 @@ def add(self, a, b):
     client = zerorpc.Client()
     client.connect(endpoint)
 
-    async_result = client.lolita(async=True)
+    async_result = client.lolita(async_=True)
     assert async_result.get() == 42
 
-    async_result = client.add(1, 4, async=True)
+    async_result = client.add(1, 4, async_=True)
     assert async_result.get() == 5
diff --git a/tests/test_heartbeat.py b/tests/test_heartbeat.py
index 75b1d29..14c66fd 100644
--- a/tests/test_heartbeat.py
+++ b/tests/test_heartbeat.py
@@ -27,7 +27,7 @@
 from __future__ import absolute_import
 from builtins import range
 
-from nose.tools import assert_raises
+import pytest
 import gevent
 import sys
 
@@ -59,9 +59,9 @@ def test_close_server_hbchan():
     print('CLOSE SERVER SOCKET!!!')
     server_hbchan.close()
     if sys.version_info < (2, 7):
-        assert_raises(zerorpc.LostRemote, client_hbchan.recv)
+        pytest.raises(zerorpc.LostRemote, client_hbchan.recv)
     else:
-        with assert_raises(zerorpc.LostRemote):
+        with pytest.raises(zerorpc.LostRemote):
             client_hbchan.recv()
     print('CLIENT LOST SERVER :)')
     client_hbchan.close()
@@ -92,9 +92,9 @@ def test_close_client_hbchan():
     print('CLOSE CLIENT SOCKET!!!')
     client_hbchan.close()
     if sys.version_info < (2, 7):
-        assert_raises(zerorpc.LostRemote, server_hbchan.recv)
+        pytest.raises(zerorpc.LostRemote, server_hbchan.recv)
     else:
-        with assert_raises(zerorpc.LostRemote):
+        with pytest.raises(zerorpc.LostRemote):
             server_hbchan.recv()
     print('SERVER LOST CLIENT :)')
     server_hbchan.close()
@@ -123,9 +123,9 @@ def test_heartbeat_can_open_channel_server_close():
     print('CLOSE SERVER SOCKET!!!')
     server_hbchan.close()
     if sys.version_info < (2, 7):
-        assert_raises(zerorpc.LostRemote, client_hbchan.recv)
+        pytest.raises(zerorpc.LostRemote, client_hbchan.recv)
     else:
-        with assert_raises(zerorpc.LostRemote):
+        with pytest.raises(zerorpc.LostRemote):
             client_hbchan.recv()
     print('CLIENT LOST SERVER :)')
     client_hbchan.close()
@@ -155,9 +155,9 @@ def test_heartbeat_can_open_channel_client_close():
     client_hbchan.close()
     client.close()
     if sys.version_info < (2, 7):
-        assert_raises(zerorpc.LostRemote, server_hbchan.recv)
+        pytest.raises(zerorpc.LostRemote, server_hbchan.recv)
     else:
-        with assert_raises(zerorpc.LostRemote):
+        with pytest.raises(zerorpc.LostRemote):
             server_hbchan.recv()
     print('SERVER LOST CLIENT :)')
     server_hbchan.close()
@@ -227,9 +227,9 @@ def client_do():
             assert list(event.args) == [x + x * x]
         client_hbchan.emit('add', (x, x * x))
         if sys.version_info < (2, 7):
-            assert_raises(zerorpc.LostRemote, client_hbchan.recv)
+            pytest.raises(zerorpc.LostRemote, client_hbchan.recv)
         else:
-            with assert_raises(zerorpc.LostRemote):
+            with pytest.raises(zerorpc.LostRemote):
                 client_hbchan.recv()
         client_hbchan.close()
 
@@ -287,9 +287,9 @@ def server_do():
             server_hbchan.emit('OK', (sum(event.args),))
 
         if sys.version_info < (2, 7):
-            assert_raises(zerorpc.LostRemote, server_hbchan.recv)
+            pytest.raises(zerorpc.LostRemote, server_hbchan.recv)
         else:
-            with assert_raises(zerorpc.LostRemote):
+            with pytest.raises(zerorpc.LostRemote):
                 server_hbchan.recv()
         server_hbchan.close()
 
@@ -322,9 +322,9 @@ def _do_with_assert_raises():
                     event = client_hbchan.recv(timeout=TIME_FACTOR * 3)
                     assert event.name == 'OK'
                     assert list(event.args) == [x]
-            assert_raises(zerorpc.TimeoutExpired, _do_with_assert_raises)
+            pytest.raises(zerorpc.TimeoutExpired, _do_with_assert_raises)
         else:
-            with assert_raises(zerorpc.TimeoutExpired):
+            with pytest.raises(zerorpc.TimeoutExpired):
                 for x in range(10):
                     client_hbchan.emit('sleep', (x,))
                     event = client_hbchan.recv(timeout=TIME_FACTOR * 3)
@@ -346,9 +346,9 @@ def _do_with_assert_raises():
                     assert event.name == 'sleep'
                     gevent.sleep(TIME_FACTOR * event.args[0])
                     server_hbchan.emit('OK', event.args)
-            assert_raises(zerorpc.LostRemote, _do_with_assert_raises)
+            pytest.raises(zerorpc.LostRemote, _do_with_assert_raises)
         else:
-            with assert_raises(zerorpc.LostRemote):
+            with pytest.raises(zerorpc.LostRemote):
                 for x in range(20):
                     event = server_hbchan.recv()
                     assert event.name == 'sleep'
diff --git a/tests/test_middleware.py b/tests/test_middleware.py
index 754f8cb..3163a3a 100644
--- a/tests/test_middleware.py
+++ b/tests/test_middleware.py
@@ -28,7 +28,7 @@
 from builtins import str
 from future.utils import tobytes
 
-from nose.tools import assert_raises
+import pytest
 import gevent
 import gevent.local
 import random
@@ -101,9 +101,9 @@ def hello(self):
 
     srv = Srv(heartbeat=TIME_FACTOR * 1, context=c)
     if sys.version_info < (2, 7):
-        assert_raises(zmq.ZMQError, srv.bind, 'some_service')
+        pytest.raises(zmq.ZMQError, srv.bind, 'some_service')
     else:
-        with assert_raises(zmq.ZMQError):
+        with pytest.raises(zmq.ZMQError):
             srv.bind('some_service')
 
     cnt = c.register_middleware(Resolver())
diff --git a/tests/test_reqstream.py b/tests/test_reqstream.py
index 5d48b4d..71e1511 100644
--- a/tests/test_reqstream.py
+++ b/tests/test_reqstream.py
@@ -28,11 +28,17 @@
 from builtins import range
 
 import gevent
-import collections
 
 import zerorpc
 from .testutils import teardown, random_ipc_endpoint, TIME_FACTOR
 
+try:
+    # Try collections.abc for 3.4+
+    from collections.abc import Iterator
+except ImportError:
+    # Fallback to collections for Python 2
+    from collections import Iterator
+
 
 def test_rcp_streaming():
     endpoint = random_ipc_endpoint()
@@ -58,7 +64,7 @@ def xrange(self, max):
     assert list(r) == list(range(10))
 
     r = client.xrange(10)
-    assert isinstance(r, collections.Iterator)
+    assert isinstance(r, Iterator)
     l = []
     print('wait 4s for fun')
     gevent.sleep(TIME_FACTOR * 4)
diff --git a/tests/test_server.py b/tests/test_server.py
index 2a266ce..86997a9 100644
--- a/tests/test_server.py
+++ b/tests/test_server.py
@@ -27,7 +27,7 @@
 from __future__ import absolute_import
 from builtins import range
 
-from nose.tools import assert_raises
+import pytest
 import gevent
 import sys
 
@@ -114,9 +114,9 @@ def add(self, a, b):
     client.connect(endpoint)
 
     if sys.version_info < (2, 7):
-        assert_raises(zerorpc.TimeoutExpired, client.add, 1, 4)
+        pytest.raises(zerorpc.TimeoutExpired, client.add, 1, 4)
     else:
-        with assert_raises(zerorpc.TimeoutExpired):
+        with pytest.raises(zerorpc.TimeoutExpired):
             print(client.add(1, 4))
     client.close()
     srv.close()
@@ -140,9 +140,9 @@ def raise_something(self, a):
     if sys.version_info < (2, 7):
         def _do_with_assert_raises():
             print(client.raise_something(42))
-        assert_raises(zerorpc.RemoteError, _do_with_assert_raises)
+        pytest.raises(zerorpc.RemoteError, _do_with_assert_raises)
     else:
-        with assert_raises(zerorpc.RemoteError):
+        with pytest.raises(zerorpc.RemoteError):
             print(client.raise_something(42))
     assert client.raise_something(list(range(5))) == 4
     client.close()
@@ -167,9 +167,9 @@ def raise_error(self):
     if sys.version_info < (2, 7):
         def _do_with_assert_raises():
             print(client.raise_error())
-        assert_raises(zerorpc.RemoteError, _do_with_assert_raises)
+        pytest.raises(zerorpc.RemoteError, _do_with_assert_raises)
     else:
-        with assert_raises(zerorpc.RemoteError):
+        with pytest.raises(zerorpc.RemoteError):
             print(client.raise_error())
     try:
         client.raise_error()
diff --git a/tests/testutils.py b/tests/testutils.py
index 2a0110c..85b6a96 100644
--- a/tests/testutils.py
+++ b/tests/testutils.py
@@ -26,7 +26,7 @@
 from builtins import str
 
 import functools
-import nose.exc
+import pytest
 import random
 import os
 
@@ -52,7 +52,7 @@ def skip(reason):
     def _skip(test):
         @functools.wraps(test)
         def wrap():
-            raise nose.exc.SkipTest(reason)
+            raise pytest.SkipTest(reason)
         return wrap
     return _skip
 
diff --git a/tox.ini b/tox.ini
index 3490b2c..96bace8 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,10 +4,10 @@ envlist = py26,py27,py34,py35
 [testenv]
 deps =
     flake8
-    nose
+    pytest
 commands =
     flake8 zerorpc bin
-    nosetests -v
+    pytest -v
 passenv = ZPC_TEST_TIME_FACTOR
 
 [flake8]
diff --git a/zerorpc/cli.py b/zerorpc/cli.py
index 2907c25..3fd6350 100644
--- a/zerorpc/cli.py
+++ b/zerorpc/cli.py
@@ -33,11 +33,17 @@
 import inspect
 import os
 import logging
-import collections
 from pprint import pprint
 
 import zerorpc
 
+try:
+    # Try collections.abc for 3.4+
+    from collections.abc import Iterator
+except ImportError:
+    # Fallback to collections for Python 2
+    from collections import Iterator
+
 
 parser = argparse.ArgumentParser(
     description='Make a zerorpc call to a remote service.'
@@ -267,7 +273,7 @@ def run_client(args):
     else:
         call_args = args.params
     results = client(args.command, *call_args)
-    if not isinstance(results, collections.Iterator):
+    if not isinstance(results, Iterator):
         if args.print_json:
             json.dump(results, sys.stdout)
         else:
diff --git a/zerorpc/core.py b/zerorpc/core.py
index 9fa63e3..ec2e008 100644
--- a/zerorpc/core.py
+++ b/zerorpc/core.py
@@ -266,7 +266,10 @@ def __call__(self, method, *args, **kargs):
         self._context.hook_client_before_request(request_event)
         bufchan.emit_event(request_event)
 
-        if kargs.get('async', False) is False:
+        # In python 3.7, "async" is a reserved keyword, clients should now use
+        # "async_": support both for the time being
+        if (kargs.get('async', False) is False and
+            kargs.get('async_', False) is False):
             return self._process_response(request_event, bufchan, timeout)
 
         async_result = gevent.event.AsyncResult()
@@ -403,7 +406,7 @@ def fork_task_context(functor, context=None):
               - task1 is created to handle this event this task will be linked
                 to the initial event context. zerorpc.Server does that for you.
               - task1 make use of some zerorpc.Client instances, the initial
-                event context is transfered on every call.
+                event context is transferred on every call.
 
               - task1 spawn a new task2.
               - task2 make use of some zerorpc.Client instances, it's a fresh
@@ -412,7 +415,7 @@ def fork_task_context(functor, context=None):
 
               - task1 spawn a new fork_task_context(task3).
               - task3 make use of some zerorpc.Client instances, the initial
-                event context is transfered on every call.
+                event context is transferred on every call.
 
         A real use case is a distributed tracer. Each time a new event is
         created, a trace_id is injected in it or copied from the current task
diff --git a/zerorpc/gevent_zmq.py b/zerorpc/gevent_zmq.py
index 9430695..54420ae 100644
--- a/zerorpc/gevent_zmq.py
+++ b/zerorpc/gevent_zmq.py
@@ -27,6 +27,13 @@
 # We want to act like zmq
 from zmq import *  # noqa
 
+try:
+    # Try to import enums for pyzmq >= 23.0.0
+    from zmq.constants import *  # noqa
+except ImportError:
+    pass
+
+
 # Explicit import to please flake8
 from zmq import ZMQError