diff --git a/Documentation/diff-config.txt b/Documentation/diff-config.txt
index 58f4bd6afa..bf955852ba 100644
--- a/Documentation/diff-config.txt
+++ b/Documentation/diff-config.txt
@@ -101,6 +101,8 @@ diff.noprefix::
 diff.orderFile::
 	File indicating how to order files within a diff, using
 	one shell glob pattern per line.
+	If `diff.orderFile` is a relative pathname, it is treated as
+	relative to the top of the working tree.
 	Can be overridden by the '-O' option to linkgit:git-diff[1].
 
 diff.renameLimit::