diff --git a/proxy/opi-proxy.service b/proxy/opi-proxy.service
index 038aa6d..b4c24b1 100644
--- a/proxy/opi-proxy.service
+++ b/proxy/opi-proxy.service
@@ -3,7 +3,7 @@ Description=OPI Proxy
 After=syslog.target
 
 [Service]
-ExecStart=/usr/bin/gunicorn -b :80 opi_proxy:app -k gevent -u nobody -g nogroup --log-syslog
+ExecStart=/usr/bin/gunicorn -b [::]:80 opi_proxy:app -k gevent -u nobody -g nogroup --log-syslog
 Environment=CONFIG=/etc/opi-proxy.json
 Restart=always
 Type=simple