diff --git a/lock-caddyfile.sh b/lock-caddyfile.sh
new file mode 100755
index 0000000..9e30552
--- /dev/null
+++ b/lock-caddyfile.sh
@@ -0,0 +1,36 @@
+#!/bin/bash
+# /opt/dashcaddy/lock-caddyfile.sh — re-apply immutable flag without breaking the container.
+# The DashCaddy container reads /etc/caddy/Caddyfile as a bind mount. chattr +i
+# propagates into the container and breaks startup validation. We apply chattr
+# +i ONLY when the container is stopped, then unlock before start.sh runs.
+#
+# SamiPanel is fully purged from this host (cron removed, binaries gone,
+# systemd unit masked to /dev/null). The structural protection does not
+# depend on the immutable flag; this is defense in depth.
+
+set -e
+ACTION="${1:-lock}"
+
+case "$ACTION" in
+  unlock)
+    chattr -i /etc/caddy/Caddyfile 2>/dev/null || true
+    echo "Caddyfile unlocked for container start"
+    ;;
+  lock)
+    # Don't lock if container is running — the bind mount would re-introduce
+    # the readonly/immutable state inside the container.
+    if docker ps --filter name=dashcaddy-api --format '{{.Names}}' | grep -q dashcaddy-api; then
+      echo "DashCaddy container is running — leaving Caddyfile mutable for the bind mount"
+    else
+      chattr +i /etc/caddy/Caddyfile
+      echo "Caddyfile locked (immutable)"
+    fi
+    ;;
+  status)
+    lsattr /etc/caddy/Caddyfile | head -1
+    ;;
+  *)
+    echo "Usage: $0 {lock|unlock|status}" >&2
+    exit 1
+    ;;
+esac