diff --git a/common/src/util/lazy-response-ads.ts b/common/src/util/lazy-response-ads.ts
index 1b491a44d8..2b263c9d5f 100644
--- a/common/src/util/lazy-response-ads.ts
+++ b/common/src/util/lazy-response-ads.ts
@@ -29,7 +29,8 @@ export function getResponseAdForSlot<T>(
   slotIndex: number,
 ): T | undefined {
   if (ads.length === 0) return undefined
-  return ads[Math.max(0, Math.floor(slotIndex)) % ads.length]
+  const safeSlotIndex = Number.isFinite(slotIndex) ? slotIndex : 0
+  return ads[Math.max(0, Math.floor(safeSlotIndex)) % ads.length]
 }
 
 export function createLazyResponseAdQueue<