diff --git a/apps/machine/src/stores/atm.ts b/apps/machine/src/stores/atm.ts
index f6b1793..98d420b 100644
--- a/apps/machine/src/stores/atm.ts
+++ b/apps/machine/src/stores/atm.ts
@@ -665,6 +665,18 @@ export const useAtmStore = defineStore('atm', () => {
         },
       })
 
+      // Watch state transitions to enable/disable validator hardware
+      watch(nestedState, (newState, oldState) => {
+        if (newState === 'insertingBills' && oldState !== 'insertingBills') {
+          console.log('[ATM] Enabling bill validator')
+          hal.enableValidator()
+        }
+        if (oldState === 'insertingBills' && newState !== 'insertingBills') {
+          console.log('[ATM] Disabling bill validator')
+          hal.disableValidator()
+        }
+      })
+
       console.log('[ATM] Fully initialized with HAL + Lightning')
     } catch (error) {
       console.error('[ATM] HAL initialization failed:', error)