diff --git a/roles/zammad/templates/nginx-zammad.conf.j2 b/roles/zammad/templates/nginx-zammad.conf.j2
index 4fbaae1c..94284549 100644
--- a/roles/zammad/templates/nginx-zammad.conf.j2
+++ b/roles/zammad/templates/nginx-zammad.conf.j2
@@ -61,6 +61,7 @@ server {
         proxy_http_version 1.1;
         proxy_set_header Upgrade $http_upgrade;
         proxy_set_header Connection "Upgrade";
+        proxy_set_header Host $http_host;
         proxy_set_header CLIENT_IP $remote_addr;
         proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
         proxy_set_header X-Forwarded-Proto $scheme;