diff --git a/templates/haproxy.cfg.j2 b/templates/haproxy.cfg.j2
index 5b2dfcd..2f38883 100644
--- a/templates/haproxy.cfg.j2
+++ b/templates/haproxy.cfg.j2
@@ -166,7 +166,7 @@ frontend shinyproxy_metrics
 {% for srv in docker_swarm_haproxy_additional_services %}
 {% if srv.mode is defined and srv.mode == 'tcp' %}
 frontend {{ srv.acl_name }}
-    bind: {{ srv.service_port }}
+    bind :{{ srv.service_port }}
     mode {{ srv.mode }}
 {% if srv.allowed_networks is defined %}
     acl {{ srv.acl_name }}_nets src {% for net in srv.allowed_networks %} {{ net }}{% endfor %}