diff --git a/doc/repo-add.8.txt b/doc/repo-add.8.txt
index 2500ab8b..75f49ef5 100644
--- a/doc/repo-add.8.txt
+++ b/doc/repo-add.8.txt
@@ -10,7 +10,7 @@ repo-add - package database maintenance utility
 
 Synopsis
 --------
-repo-add [-f] [-q] <path-to-db> <package1> [<package2> ...]
+repo-add [-d] [-f] [-q] <path-to-db> <package1> [<package2> ...]
 
 repo-remove [-q] <path-to-db> <packagename> [<packagename2> ...]
 
@@ -30,6 +30,10 @@ on the command line.
 
 Options
 -------
+*-d, \--delta*::
+	Automatically generate and add a delta file between the old entry and the
+	new one, if the old package file is found next to the new one.
+
 *-f, \--files*::
 	Tells repo-add also to create and include a list of the files in the
 	specified packages. This is useful for creating databases listing all files