diff --git a/assets/js/sw/download.ts b/assets/js/sw/download.ts
index 466fd835..27a774ed 100644
--- a/assets/js/sw/download.ts
+++ b/assets/js/sw/download.ts
@@ -15,15 +15,15 @@ export function handleDownload(event: FetchEvent, url: URL): void {
     return event.respondWith(new Response('Don\'t know what to download!', { status: 400 }));
   }
 
-  const generateResponse = ifOk((upstream: Response) => {
-    const headers = new Headers(upstream.headers);
+  const response =
+    fetch(target)
+      .then(ifOk((upstream: Response) => {
+        const headers = new Headers(upstream.headers);
 
-    headers.set('content-disposition', `attachment; filename="${escapeFilename(name)}"`);
+        headers.set('content-disposition', `attachment; filename="${escapeFilename(name)}"`);
 
-    return new Response(upstream.body, { headers });
-  });
+        return new Response(upstream.body, { headers });
+      }));
 
-  fetch(target)
-    .then(generateResponse)
-    .then(event.respondWith);
+  event.respondWith(response);
 }
diff --git a/assets/js/utils/requests.js b/assets/js/utils/requests.js
index 91c9277a..241593f4 100644
--- a/assets/js/utils/requests.js
+++ b/assets/js/utils/requests.js
@@ -70,7 +70,7 @@ function fetchBackoff(...fetchArgs) {
  */
 function escapeFilename(name) {
   return name
-    .replace(/[^-_+a-zA-Z0-9]/, '_')
+    .replace(/[^.-_+a-zA-Z0-9]/, '_')
     .substring(0, 150);
 }
 
@@ -82,7 +82,7 @@ function escapeFilename(name) {
  */
 function ifOk(responseGenerator) {
   return resp => {
-    if (resp.ok) return new Response(responseGenerator(resp));
+    if (resp.ok) return responseGenerator(resp);
     return resp;
   };
 }