diff --git a/Documentation/git-config.txt b/Documentation/git-config.txt
index 2d6ef32a08..4ba17c187b 100644
--- a/Documentation/git-config.txt
+++ b/Documentation/git-config.txt
@@ -240,6 +240,10 @@ GIT_CONFIG::
 	Using the "--global" option forces this to ~/.gitconfig. Using the
 	"--system" option forces this to $(prefix)/etc/gitconfig.
 
+GIT_CONFIG_NOSYSTEM::
+	Whether to skip reading settings from the system-wide
+	$(prefix)/etc/gitconfig file. See linkgit:git[1] for details.
+
 See also <<FILES>>.
 
 
diff --git a/Documentation/git.txt b/Documentation/git.txt
index 27da0eb209..96712889f8 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt
@@ -771,6 +771,14 @@ for further details.
 	and read the password from its STDOUT. See also the 'core.askpass'
 	option in linkgit:git-config[1].
 
+'GIT_CONFIG_NOSYSTEM'::
+	Whether to skip reading settings from the system-wide
+	`$(prefix)/etc/gitconfig` file.  This environment variable can
+	be used along with `$HOME` and `$XDG_CONFIG_HOME` to create a
+	predictable environment for a picky script, or you can set it
+	temporarily to avoid using a buggy `/etc/gitconfig` file while
+	waiting for someone with sufficient permissions to fix it.
+
 'GIT_FLUSH'::
 	If this environment variable is set to "1", then commands such
 	as 'git blame' (in incremental mode), 'git rev-list', 'git log',