diff --git a/app/Services/SlotService.php b/app/Services/SlotService.php
index 6eb0918..cfb8bb9 100644
--- a/app/Services/SlotService.php
+++ b/app/Services/SlotService.php
@@ -136,7 +136,7 @@ class SlotService
         return max(0, $slot->remaining - $activeHolds);
     }
 
-    private function findHoldByIdempotencyKey(string $idempotencyKey): Hold
+    private function findHoldByIdempotencyKey(string $idempotencyKey): ?Hold
     {
         return Hold::query()
             ->where('idempotency_key', $idempotencyKey)
diff --git a/routes/api.php b/routes/api.php
index 5ea0300..19d7221 100644
--- a/routes/api.php
+++ b/routes/api.php
@@ -9,5 +9,5 @@ Route::get('/slots/availability', [AvailabilityController::class, 'index']);
 Route::post('/slots/{slot}/hold', [HoldController::class, 'store'])
     ->middleware('idempotency');
 
-Route::post('/holds/{id}/confirm', [HoldController::class, 'confirm']);
-Route::delete('/holds/{id}', [HoldController::class, 'destroy']);
+Route::post('/holds/{hold}/confirm', [HoldController::class, 'confirm']);
+Route::delete('/holds/{hold}', [HoldController::class, 'destroy']);