diff --git a/frontend/src/app.d.ts b/frontend/src/app.d.ts
index e5e13f7..99ea21c 100644
--- a/frontend/src/app.d.ts
+++ b/frontend/src/app.d.ts
@@ -13,6 +13,7 @@ declare global {
 		__walkInCountdownInterval?: ReturnType<typeof setInterval>;
 		__walkInModalCountdownInterval?: ReturnType<typeof setInterval>;
 		__bookingCreateCountdownInterval?: ReturnType<typeof setInterval>;
+		__bookingFlowCountdownInterval?: ReturnType<typeof setInterval> | null;
 	}
 }
 
diff --git a/frontend/src/lib/components/booking/BookingFlow.svelte b/frontend/src/lib/components/booking/BookingFlow.svelte
index 62cb08b..5049d4c 100644
--- a/frontend/src/lib/components/booking/BookingFlow.svelte
+++ b/frontend/src/lib/components/booking/BookingFlow.svelte
@@ -27,12 +27,6 @@
 	import { onDestroy } from 'svelte';
 	import { SvelteDate } from 'svelte/reactivity';
 
-	declare global {
-		interface Window {
-			__bookingFlowCountdownInterval?: ReturnType<typeof setInterval> | null;
-		}
-	}
-
 	// Components
 	import BookingActions from '$lib/components/booking/BookingActions.svelte';
 	import BookingSummary from '$lib/components/booking/BookingSummary.svelte';
@@ -688,7 +682,7 @@
 		loadingAvailableHours = true;
 
 		try {
-			const authHeaders = authStore.currentToken ? { Authorization: `Bearer ${authStore.currentToken}` } : {};
+			const authHeaders: RequestInit['headers'] = authStore.currentToken ? { Authorization: `Bearer ${authStore.currentToken}` } : undefined;
 			const [whRes, ahRes] = await Promise.all([
 				fetch(`/api/scheduling/working-hours?start=${startStr}&end=${endStr}`, { headers: authHeaders }),
 				fetch(`/api/scheduling/available-hours?start=${startStr}&end=${endStr}`, { headers: authHeaders })
@@ -782,7 +776,7 @@
 			const startStr = startOfMonth.toString();
 			const endStr = endOfMonth.toString();
 
-			const authHeaders = authStore.currentToken ? { Authorization: `Bearer ${authStore.currentToken}` } : {};
+			const authHeaders: RequestInit['headers'] = authStore.currentToken ? { Authorization: `Bearer ${authStore.currentToken}` } : undefined;
 
 			// Fetch working hours
 			const workingHoursResponse = await fetch(