diff --git a/dev-requirements.txt b/dev-requirements.txt
index 39b5fb8..27e5063 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -20,6 +20,3 @@ prospector[with_pyroma]==1.1.6.2; python_version <= "3.5"
 
 pyflakes==2.2.0; python_version >= "3.7"
 pyflakes==1.6.0; python_version < "3.7"
-
-cryptography==3.0; python_version == "3.5"
-cryptography==2.9; python_version == "2.7"
diff --git a/setup.py b/setup.py
index c57c327..8300718 100644
--- a/setup.py
+++ b/setup.py
@@ -12,10 +12,13 @@
     'cliff==2.7.0',
     'stevedore>=1.10.0',
     'requests>=2.7.0',
-    'cryptography>=1.3.1',
+    'cryptography>=1.3.1; python_version >= "3.6"',
+    'cryptography==3.0; python_version == "3.5"',
+    'cryptography==2.9; python_version == "2.7"',
     'six>=1.10.0',
     'ndg-httpsclient>=0.4.0',
-    'pyopenssl>=0.15.1',
+    'pyopenssl>=0.15.1; python_version >= "3.6"',
+    'pyopenssl>=0.15.1,<=19.1.0; python_version == "2.7" or python_version == "3.5"',
     'cached-property>=1.3.0',
     'paramiko>=1.16.0',
     'pathlib2>=2.1.0',