diff --git a/scripts/openvpn/removeOVPN.sh b/scripts/openvpn/removeOVPN.sh
index 79a5936..d8e1061 100755
--- a/scripts/openvpn/removeOVPN.sh
+++ b/scripts/openvpn/removeOVPN.sh
@@ -76,6 +76,7 @@ if [[ -z "${CERTS_TO_REVOKE}" ]]; then
         exit 1
     fi
 
+    re='^[0-9]+$'
     if [[ ${NAME} =~ $re ]] ; then
         NAME=${CERTS[$(($NAME))]}
     fi