1 files changed, 2 insertions, 1 deletions

diff --git a/setup.cfg b/setup.cfg
index c89810ab..91c59cb6 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -11,7 +11,8 @@ provides-extra =
     secure
     socks
 requires-dist =
-    pyOpenSSL>=0.14; python_version<="2.7" and extra == 'secure'
+    pyOpenSSL>=0.14,<18.0.0; python_version=="2.6" and extra == 'secure'
+    pyOpenSSL>=0.14; python_version=="2.7" and extra == 'secure'
     cryptography>=1.3.4; python_version<="2.7" and extra == 'secure'
     idna>=2.0.0; python_version<="2.7" and extra == 'secure'
     certifi; extra == 'secure'