diff --git a/src/client/scripts/idb-proxy.ts b/src/client/scripts/idb-proxy.ts
index 70d2b19bb8..c0d01e6292 100644
--- a/src/client/scripts/idb-proxy.ts
+++ b/src/client/scripts/idb-proxy.ts
@@ -7,7 +7,7 @@ import {
 
 const fallbackName = (key: string) => `idbfallback::${key}`;
 
-let idbAvailable = window ? !!window.indexedDB : true;
+let idbAvailable = typeof window !== 'undefined' ? !!window.indexedDB : true;
 
 if (idbAvailable) {
 	try {