diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index 77a3f78dd75514667b77ae4e1dbbb3731b05a33d..1689c748171a8ff48395cf432aabe0130fc6b8d2 100644
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -164,5 +164,8 @@
 	That is, it exits with 1 if there were differences and
 	0 means no differences.
 
+--quiet::
+	Disable all output of the program. Implies --exit-code.
+
 For more detailed explanation on these common options, see also
 link:diffcore.html[diffcore documentation].