diff --git a/modules/clan/phonebox/default.nix b/modules/clan/phonebox/default.nix
index 462910fa..6cde7801 100644
--- a/modules/clan/phonebox/default.nix
+++ b/modules/clan/phonebox/default.nix
@@ -256,6 +256,13 @@
               '';
             };
 
+            # Phonebox nodes are headless and unattended. Observed on mirach/almach
+            # (2026-07..09): hard hangs leave no journal/pstore trace and stay down
+            # until someone power-cycles the board. Arm the hardware watchdog so a
+            # hung kernel/PID1 resets itself, and reboot instead of halting on panic.
+            systemd.settings.Manager.RuntimeWatchdogSec = "30s";
+            boot.kernel.sysctl."kernel.panic" = 10;
+
             networking.interfaces = {
               ${ata-interface} = {
                 useDHCP = false;