diff --git a/git-applypatch.sh b/git-applypatch.sh
index a112e1a504..214f5c31a6 100755
--- a/git-applypatch.sh
+++ b/git-applypatch.sh
@@ -10,8 +10,12 @@
 ##	$3 - "info" file with Author, email and subject
 ##	$4 - optional file containing signoff to add
 ##
+
+USAGE='<msg> <patch> <info> [<signoff>]'
 . git-sh-setup
 
+[[ "$#" = "3" || "$#" = "4" ]] || usage
+
 final=.dotest/final-commit
 ##
 ## If this file exists, we ask before applying