diff --git a/bin/regen-certs b/bin/regen-certs
index aa5d0d55..b8bfd3e6 100755
--- a/bin/regen-certs
+++ b/bin/regen-certs
@@ -1,72 +1,77 @@
 #!/bin/bash
 
 base_dir=$(dirname $(dirname $0))
 
 cert_dir="${base_dir}/docker/certs/"
 
 if [ ! -d "${cert_dir}" ]; then
     mkdir -p ${cert_dir}
 fi
 
 if [ ! -f "${cert_dir}/ca.key" ]; then
     openssl genrsa -out ${cert_dir}/ca.key 4096
 
     openssl req \
         -new \
         -x509 \
         -nodes \
         -days 3650 \
         -key ${cert_dir}/ca.key \
         -out ${cert_dir}/ca.cert \
         -subj '/O=Example CA/'
 fi
 
 if [ -f /etc/pki/tls/openssl.cnf ]; then
     openssl_cnf="/etc/pki/tls/openssl.cnf"
 elif [ -f /etc/ssl/openssl.cnf ]; then
     openssl_cnf="/etc/ssl/openssl.cnf"
 else
     echo "No openssl.cnf"
     exit 1
 fi
 
-APP_DOMAIN=$(grep APP_DOMAIN .env | tail -n1 | sed "s/APP_DOMAIN=//")
+if [ "$#" -eq  "0" ]; then
+    APP_DOMAIN=$(grep -P "^APP_DOMAIN=.*" .env | tail -n1 | sed "s/APP_DOMAIN=//")
+    DOMAINS="kolab.mgmt.com kolab.hosted.com imap.hosted.com admin.${APP_DOMAIN} meet.${APP_DOMAIN}"
+else
+    DOMAINS=$1
+fi
 
-for name in kolab.mgmt.com kolab.hosted.com imap.hosted.com {{admin,meet}.,}${APP_DOMAIN}; do
+for name in $DOMAINS; do
     openssl genrsa -out ${cert_dir}/${name}.key 4096
 
     openssl req \
         -new \
         -key ${cert_dir}/${name}.key \
         -out ${cert_dir}/${name}.csr \
         -subj "/O=Example CA/CN=${name}/" \
         -reqexts SAN \
         -config <(cat ${openssl_cnf} \
             <(printf "[SAN]\nsubjectAltName=DNS:${name}"))
 
     openssl x509 \
         -req \
         -in ${cert_dir}/${name}.csr \
         -CA ${cert_dir}/ca.cert \
         -CAkey ${cert_dir}/ca.key \
         -CAcreateserial \
         -out ${cert_dir}/${name}.cert \
         -days 28 \
         -extfile <(cat ${openssl_cnf} \
             <(printf "[SAN]\nsubjectAltName=DNS:${name}")) \
         -extensions SAN
 
     # 'cause java ...
     openssl pkcs8 \
         -topk8 \
         -inform pem \
         -in ${cert_dir}/${name}.key \
         -outform pem \
         -nocrypt \
         -out ${cert_dir}/${name}_p8.key
 
     cat ${cert_dir}/${name}.cert \
         ${cert_dir}/ca.cert > ${cert_dir}/${name}.chain.pem
 
     chmod 644 ${cert_dir}/*.{cert,key,pem}
 done