diff --git a/openup b/openup
index 8b74d73..617decf 100755
--- a/openup
+++ b/openup
@@ -37,7 +37,7 @@ VUXML_URL="https://stable.mtier.org/vuxml/$(uname -r | tr -d '.').xml"
 ########################################################################
 
 
-_OPENUP_VERSION=12
+_OPENUP_VERSION=13
 _OPENUP_MINREL=53
 
 usage() {
@@ -75,7 +75,10 @@ fi
 set -A _REL -- $(sysctl -n kern.version | sed 's/^OpenBSD \([0-9]\.[0-9]\)\([^ ]*\).*/\1 \2/;q')
 _REL_INT="$(echo ${_REL[0]} | tr -d '.')"
 
-if [ "${_REL[1]}" == -!(stable) -o "${_REL_INT}" -lt "${_OPENUP_MINREL}" ]; then
+if [ -n "${_REL[1]}" -a "${_REL[1]}" != "-stable" ]; then _badrel=1; fi
+if [ "${_REL_INT}" -lt "${_OPENUP_MINREL}" ]; then _badrel=1; fi
+
+if [ -n "${_badrel}" ]; then
 	pr_error "${_REL[0]}${_REL[1]} is not a supported release"
 	exit 1
 fi