diff --git a/web/packages/new/photos/services/download.ts b/web/packages/new/photos/services/download.ts
index ef41873f39..c9cfa38802 100644
--- a/web/packages/new/photos/services/download.ts
+++ b/web/packages/new/photos/services/download.ts
@@ -56,16 +56,12 @@ class DownloadManagerImpl {
 
     private fileObjectURLPromises = new Map<number, Promise<SourceURLs>>();
     private fileConversionPromises = new Map<number, Promise<SourceURLs>>();
-    private thumbnailObjectURLPromises = new Map<number, Promise<string>>();
+    private thumbnailObjectURLPromises = new Map<number, Promise<string | undefined>>();
 
     private fileDownloadProgress = new Map<number, number>();
 
     private progressUpdater: (value: Map<number, number>) => void = () => {};
 
-    private ensureClient() {
-        return ensure(this.downloadClient);
-    }
-
     async init(token?: string) {
         if (this.ready) {
             log.info("DownloadManager already initialized");
@@ -140,14 +136,14 @@ class DownloadManagerImpl {
         const key = file.id.toString();
         const cached = await this.thumbnailCache?.get(key);
         if (cached) return new Uint8Array(await cached.arrayBuffer());
-        if (localOnly) return null;
+        if (localOnly) return undefined;
 
         const thumb = await this.downloadThumb(file);
         await this.thumbnailCache?.put(key, new Blob([thumb]));
         return thumb;
     }
 
-    async getThumbnailForPreview(file: EnteFile, localOnly = false) {
+    async getThumbnailForPreview(file: EnteFile, localOnly = false): Promise<string | undefined> {
         this.ensureInitialized();
         try {
             if (!this.thumbnailObjectURLPromises.has(file.id)) {