diff --git a/resources/chaosknoten/lists/docker_compose/compose.yaml.j2 b/resources/chaosknoten/lists/docker_compose/compose.yaml.j2
index 7a109e8c..572b6dfc 100644
--- a/resources/chaosknoten/lists/docker_compose/compose.yaml.j2
+++ b/resources/chaosknoten/lists/docker_compose/compose.yaml.j2
@@ -62,7 +62,7 @@ services:
       - POSTGRES_DB=mailmandb
       - POSTGRES_USER=mailman
       - "POSTGRES_PASSWORD={{ secret__lists__postgres_password }}"
-    image: docker.io/library/postgres:12-alpine
+    image: docker.io/library/postgres:15-alpine
     volumes:
       - /opt/mailman/database:/var/lib/postgresql/data
     networks:
diff --git a/resources/chaosknoten/public-reverse-proxy/nginx/nginx.conf b/resources/chaosknoten/public-reverse-proxy/nginx/nginx.conf
index c7be7563..04b310a1 100644
--- a/resources/chaosknoten/public-reverse-proxy/nginx/nginx.conf
+++ b/resources/chaosknoten/public-reverse-proxy/nginx/nginx.conf
@@ -3,6 +3,7 @@
 
 user  nginx;
 worker_processes  auto;
+worker_rlimit_nofile  2050; # should be worker_connections*2 at least
 
 error_log  /var/log/nginx/error.log notice;
 pid        /var/run/nginx.pid;