diff --git a/roles/docker-reverse-proxy/templates/proxy_pass.conf.j2 b/roles/docker-reverse-proxy/templates/proxy_pass.conf.j2
index 542b25b6..434a592c 100644
--- a/roles/docker-reverse-proxy/templates/proxy_pass.conf.j2
+++ b/roles/docker-reverse-proxy/templates/proxy_pass.conf.j2
@@ -8,6 +8,11 @@ location /
   proxy_set_header X-Forwarded-Proto https;
   proxy_set_header X-Forwarded-Port 443;
 
+  # WebSocket specific header
+  proxy_http_version 1.1;
+  proxy_set_header Upgrade $http_upgrade;
+  proxy_set_header Connection "upgrade";
+
   # deactivate buffering
   proxy_buffering off;
   proxy_request_buffering off;