--- easyrsa.orig	2020-09-09 20:59:45 UTC
+++ easyrsa
@@ -1546,7 +1546,7 @@ default_server_san() {
 		easyrsa_openssl req -in "$path" -noout -subject -nameopt sep_multiline |
 		awk -F'=' '/^  *CN=/{print $2}'
 		)
-	echo "$cn" | grep -E -q '^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$'
+	echo "$cn" | grep -E -q '^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$'
 	#shellcheck disable=SC2181
 	if [ $? -eq 0 ]; then
 		print "subjectAltName = IP:$cn"
