diff --git a/once/update.sh b/once/update.sh
index 6962973..d93a461 100755
--- a/once/update.sh
+++ b/once/update.sh
@@ -21,6 +21,10 @@ if [ "$tarballs" = '/updates/*.tar.gz' ]; then
 	exit 0
 fi
 
+if [ -f /etc/vendor.cfg ]; then
+	. /etc/vendor.cfg
+fi
+
 for tarball in $tarballs; do
 	tarball="${tarball##*/}"
 
@@ -38,9 +42,27 @@ for tarball in $tarballs; do
 		pkgdir=/tarballs/archive/${tarball%%.tar.gz}/
 		mkdir -p $pkgdir
 		printf '%s\n' "$pkgsig" >> ${pkgdir}/pkgsigs.log
-		pkgdir=$pkgdir/$pkgsig/
-		mkdir -p $pkgdir
-		mv /tarballs/$tarball $pkgdir
+		mkdir -p $pkgdir/$pkgsig/
+		mv /tarballs/$tarball $pkgdir/$pkgsig/
+
+		case ${keep:-'-1'} in
+			-1 )
+				;;
+
+			* )
+				tail -n ${keep} ${pkgdir}/pkgsigs.log > ${pkgdir}/pkgsigs.keep
+
+				for pkgsigdir in ${pkgdir}/*; do
+					if [ -d $pkgsigdir ]; then
+						if ! grep ${pkgsigdir##*/} ${pkgdir}/pkgsigs.keep; then
+							rm    $pkgsigdir/$tarball
+							rmdir $pkgsigdir
+						fi
+					fi
+				done
+
+				;;
+		esac
 	fi
 
 	echo caching the current $tarball