diff --git a/abuild-sign.in b/abuild-sign.in
index 4f38a0c..ce7baa5 100644
--- a/abuild-sign.in
+++ b/abuild-sign.in
@@ -46,7 +46,9 @@ usage() {
 	cat >&2 <<__EOF__
 $program $program_version - sign indexes
 Usage: $program [-k PRIVKEY] [-p PUBKEY] INDEXFILE...
+       $program -e
 Options:
+  -e, --installed    Check only of there exist a private key for signing
   -k, --private KEY  The private key to use for signing
   -p, --public KEY   The name of public key. apk add will look for
                      /etc/apk/keys/KEY
@@ -56,11 +58,12 @@ Options:
 __EOF__
 }
 
+check_installed=false
 privkey="$PACKAGER_PRIVKEY"
 pubkey=
 quiet=
 
-args=`getopt -o k:p:qh --long private:,public:,quiet,help -n "$program" -- "$@"`
+args=`getopt -o ek:p:qh --long installed,private:,public:,quiet,help -n "$program" -- "$@"`
 if [ $? -ne 0 ]; then
 	usage
 	exit 2
@@ -68,6 +71,7 @@ fi
 eval set -- "$args"
 while true; do
 	case $1 in
+		-e|--installed) check_installed=true;;
 		-k|--private) privkey=$2; shift;;
 		-p|--public) pubkey=$2; shift;;
 		-q|--quiet) quiet=1;; # suppresses msg
@@ -77,7 +81,7 @@ while true; do
 	esac
 	shift
 done
-if [ $# -eq 0 ]; then
+if [ $# -eq 0 ] && ! $check_installed; then
 	usage
 	exit 2
 fi
@@ -99,5 +103,6 @@ if [ -z "$pubkey" ]; then
 	pubkey=${PACKAGER_PUBKEY:-"${privkey}.pub"}
 fi
 
-do_sign "$@"
-exit 0
+if ! $check_installed; then
+	do_sign "$@"
+fi