diff --git a/Doc/using/unix.rst b/Doc/using/unix.rst
index 09dd5b0..1d1fa8b 100644
--- a/Doc/using/unix.rst
+++ b/Doc/using/unix.rst
@@ -135,6 +135,7 @@
 
 To use shell commands in your Python scripts, look at the :mod:`subprocess` module.
 
+.. _unix_custom_openssl:
 
 Custom OpenSSL
 ==============