diff --git a/OpenSSL/SSL.py b/OpenSSL/SSL.py
index 8972097..eb26e76 100644
--- a/OpenSSL/SSL.py
+++ b/OpenSSL/SSL.py
@@ -1,5 +1,6 @@
+import six
 from warnings import warn
-from sys import platform, version_info
+from sys import platform
 from functools import wraps, partial
 from itertools import count
 from weakref import WeakValueDictionary
@@ -314,12 +315,10 @@
 
         # Backward compatibility
         if isinstance(cafile, _text_type):
-            if version_info.major == 2:
+            if six.PY2:
                 warn("unicode in cafile is no longer accepted, use bytes", DeprecationWarning)
-            elif version_info.major == 3:
-                warn("str in cafile is no longer accepted, use bytes", DeprecationWarning)
             else:
-                warn("text in cafile is no longer accepted, use bytes", DeprecationWarning)
+                warn("str in cafile is no longer accepted, use bytes", DeprecationWarning)
             cafile = cafile.encode('utf-8')
 
         if cafile is None:
@@ -985,12 +984,10 @@
 
         # Backward compatibility
         if isinstance(buf, _text_type):
-            if version_info.major == 2:
+            if six.PY2:
                 warn("unicode in buf is no longer accepted, use bytes", DeprecationWarning)
-            elif version_info.major == 3:
-                warn("str in buf is no longer accepted, use bytes", DeprecationWarning)
             else:
-                warn("text in buf is no longer accepted, use bytes", DeprecationWarning)
+                warn("str in buf is no longer accepted, use bytes", DeprecationWarning)
             buf = buf.encode('utf-8')
 
         if isinstance(buf, _memoryview):
@@ -1020,12 +1017,10 @@
 
         # Backward compatibility
         if isinstance(buf, _text_type):
-            if version_info.major == 2:
+            if six.PY2:
                 warn("unicode in buf is no longer accepted, use bytes", DeprecationWarning)
-            elif version_info.major == 3:
-                warn("str in buf is no longer accepted, use bytes", DeprecationWarning)
             else:
-                warn("text in buf is no longer accepted, use bytes", DeprecationWarning)
+                warn("str in buf is no longer accepted, use bytes", DeprecationWarning)
             buf = buf.encode('utf-8')
 
         if isinstance(buf, _memoryview):
@@ -1116,12 +1111,10 @@
 
         # Backward compatibility
         if isinstance(buf, _text_type):
-            if version_info.major == 2:
+            if six.PY2:
                 warn("unicode in buf is no longer accepted, use bytes", DeprecationWarning)
-            elif version_info.major == 3:
-                warn("str in vuf is no longer accepted, use bytes", DeprecationWarning)
             else:
-                warn("text in buf is no longer accepted, use bytes", DeprecationWarning)
+                warn("str in buf is no longer accepted, use bytes", DeprecationWarning)
             buf = buf.encode("ascii")
 
         if self._into_ssl is None: