diff --git a/Cabal/doc/installing-packages.rst b/Cabal/doc/installing-packages.rst
index b61b9e2b4e625c5a71c2533d1cdfec234b2f36fc..d28aa7f45a2a2b9306f5610cbf79644f4a251a5c 100644
--- a/Cabal/doc/installing-packages.rst
+++ b/Cabal/doc/installing-packages.rst
@@ -15,6 +15,10 @@ explicitly ask ``cabal`` to create it for you using
 
     $ cabal user-config update
 
+You can change the location of the global configuration file by specifying
+either ``--config-file=FILE`` on the command line or by setting the
+``CABAL_CONFIG`` environment variable.
+
 Most of the options in this configuration file are also available as
 command line arguments, and the corresponding documentation can be used
 to lookup their meaning. The created configuration file only specifies