diff --git a/docker-compose.yml b/docker-compose.yml
index 3411bae..f6d1b3d 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -1,3 +1,5 @@
+version: "3.9"
+
 services:
   certgen:
     image: alpine:3.20
@@ -21,12 +23,12 @@ services:
     image: haproxy:3.2
     depends_on: [certgen]
     command: >
-      sh -c '
-        for i in 1 2 3 4 5; do
-          [ -f /certs/selfsigned.pem ] && break;
-          sleep 1;
-        done;
-        haproxy -f /usr/local/etc/haproxy/haproxy.cfg
+      sh -euc '
+        for i in $(seq 1 15); do
+          [ -f /certs/selfsigned.pem ] && break
+          sleep 1
+        done
+        exec haproxy -f /usr/local/etc/haproxy/haproxy.cfg
       '
     volumes:
       - ./haproxy/haproxy.cfg:/usr/local/etc/haproxy/haproxy.cfg:ro