diff --git a/web/src/lib/libav.ts b/web/src/lib/libav.ts
index 0d09c38f..63e0c0e2 100644
--- a/web/src/lib/libav.ts
+++ b/web/src/lib/libav.ts
@@ -120,12 +120,7 @@ export default class LibAVWrapper {
                 outputName
             ]);
 
-            const file = new File(
-                [ await storage.res() ],
-                outputName,
-                { type: output.type }
-            );
-
+            const file = Storage.retype(await storage.res(), output.type);
             if (file.size === 0) return;
 
             return file;
diff --git a/web/src/lib/storage/index.ts b/web/src/lib/storage/index.ts
index 2ddeb15e..8687eb3c 100644
--- a/web/src/lib/storage/index.ts
+++ b/web/src/lib/storage/index.ts
@@ -13,3 +13,7 @@ export function init(expectedSize?: number): Promise<AbstractStorage> {
 
     throw "no storage method is available";
 }
+
+export function retype(file: File, type: string) {
+    return new File([ file ], file.name, { type });
+}
diff --git a/web/src/lib/task-manager/workers/fetch.ts b/web/src/lib/task-manager/workers/fetch.ts
index 5b84ee1e..3277071d 100644
--- a/web/src/lib/task-manager/workers/fetch.ts
+++ b/web/src/lib/task-manager/workers/fetch.ts
@@ -76,9 +76,7 @@ const fetchFile = async (url: string) => {
             return error("tunnel is broken");
         }
 
-        const file = new File(
-            [ await storage.res() ], '', { type: contentType }
-        );
+        const file = Storage.retype(await storage.res(), contentType);
 
         if (contentLength && Number(contentLength) !== file.size) {
             return error("file was not downloaded fully");