diff --git a/doc/api/ssl.rst b/doc/api/ssl.rst
index ecafbef..2ab29fd 100644
--- a/doc/api/ssl.rst
+++ b/doc/api/ssl.rst
@@ -600,7 +600,9 @@
 
 .. py:method:: Connection.get_protocol_version()
 
-    Retrieve the version of the SSL or TLS protocol used by the Connection
+    Retrieve the version of the SSL or TLS protocol used by the Connection.  For
+    example, it will return ``TLSv1`` for connections made over TLS version 1, or 
+    ``Unknown`` for connections that were not successfully established.
 
 
 .. py:method:: Connection.get_client_ca_list()