diff --git a/docs/hazmat/bindings/openssl.rst b/docs/hazmat/bindings/openssl.rst
index 194eeb9..d6bfa67 100644
--- a/docs/hazmat/bindings/openssl.rst
+++ b/docs/hazmat/bindings/openssl.rst
@@ -21,5 +21,5 @@
         and access constants.
 
 
-.. _`CFFI`: http://cffi.readthedocs.org/
+.. _`CFFI`: https://cffi.readthedocs.org/
 .. _`OpenSSL`: https://www.openssl.org/