diff --git a/setup.py b/setup.py
index d86c0f285..aa064c508 100644
--- a/setup.py
+++ b/setup.py
@@ -19,14 +19,14 @@ def has_environment_marker_platform_impl_support():
 
 
 install_requires = [
-    'Twisted>=17.9.0',
-    'cryptography>=2.0',
+    'Twisted>=18.9.0',
+    'cryptography>=3.3',
     'cssselect>=0.9.1',
     'itemloaders>=1.0.1',
     'parsel>=1.5.0',
-    'pyOpenSSL>=16.2.0',
+    'pyOpenSSL>=21.0.0',
     'queuelib>=1.4.2',
-    'service_identity>=16.0.0',
+    'service_identity>=18.1.0',
     'w3lib>=1.17.0',
     'zope.interface>=4.1.3',
     'protego>=0.1.15',
diff --git a/tests/test_crawler.py b/tests/test_crawler.py
index 1ff2e8a67..4801ad871 100644
--- a/tests/test_crawler.py
+++ b/tests/test_crawler.py
@@ -316,7 +316,7 @@ class CrawlerProcessSubprocess(ScriptRunnerMixin, unittest.TestCase):
 
     def test_reactor_default_twisted_reactor_select(self):
         log = self.run_script('reactor_default_twisted_reactor_select.py')
-        if platform.system() == 'Windows':
+        if platform.system() in ['Windows', 'Darwin']:
             # The goal of this test function is to test that, when a reactor is
             # installed (the default one here) and a different reactor is
             # configured (select here), an error raises.
diff --git a/tox.ini b/tox.ini
index aba94d79d..21ed90b5f 100644
--- a/tox.ini
+++ b/tox.ini
@@ -75,16 +75,16 @@ commands =
 
 [pinned]
 deps =
-    cryptography==2.0
+    cryptography==3.3
     cssselect==0.9.1
     h2==3.0
     itemadapter==0.1.0
     parsel==1.5.0
     Protego==0.1.15
-    pyOpenSSL==16.2.0
+    pyOpenSSL==21.0.0
     queuelib==1.4.2
-    service_identity==16.0.0
-    Twisted[http2]==17.9.0
+    service_identity==18.1.0
+    Twisted[http2]==18.9.0
     w3lib==1.17.0
     zope.interface==4.1.3
     -rtests/requirements.txt