diff --git a/packages/playwright-core/src/server/registry/oopDownloadMain.ts b/packages/playwright-core/src/server/registry/oopDownloadMain.ts
index 290e8de70a..013fbbe18d 100644
--- a/packages/playwright-core/src/server/registry/oopDownloadMain.ts
+++ b/packages/playwright-core/src/server/registry/oopDownloadMain.ts
@@ -63,12 +63,20 @@ function downloadFile(url: string, destinationPath: string, options: DownloadFil
           .on('error', handleError);
       return;
     }
-    const file = fs.createWriteStream(destinationPath);
-    file.on('finish', () => promise.resolve());
-    file.on('error', error => promise.reject(error));
-    response.pipe(file);
     totalBytes = parseInt(response.headers['content-length'] || '0', 10);
     log(`-- total bytes: ${totalBytes}`);
+    const file = fs.createWriteStream(destinationPath);
+    file.on('finish', () => {
+      if (downloadedBytes !== totalBytes) {
+        log(`-- download failed, size mismatch: ${downloadedBytes} != ${totalBytes}`);
+        promise.reject(new Error(`Download failed: size mismatch, file size: ${downloadedBytes}, expected size: ${totalBytes} URL: ${url}`));
+      } else {
+        log(`-- download complete, size: ${downloadedBytes}`);
+        promise.resolve();
+      }
+    });
+    file.on('error', error => promise.reject(error));
+    response.pipe(file);
     response.on('data', onData);
   }, (error: any) => promise.reject(error));
   return promise;
diff --git a/tests/installation/playwright-cdn-failover-should-work.spec.ts b/tests/installation/playwright-cdn-failover-should-work.spec.ts
index 49ff405a90..74dd05166b 100644
--- a/tests/installation/playwright-cdn-failover-should-work.spec.ts
+++ b/tests/installation/playwright-cdn-failover-should-work.spec.ts
@@ -21,12 +21,12 @@ const CDNS = [
   'https://playwright-verizon.azureedge.net',
 ];
 
-const DL_STAT_BLOCK = /^.*from url: (.*)$\n^.*to location: (.*)$\n^.*response status code: (.*)$\n^.*total bytes: (.*)$\n^.*SUCCESS downloading (\w+) .*$/gm;
+const DL_STAT_BLOCK = /^.*from url: (.*)$\n^.*to location: (.*)$\n^.*response status code: (.*)$\n^.*total bytes: (\d+)$\n^.*download complete, size: (\d+)$\n^.*SUCCESS downloading (\w+) .*$/gm;
 
 const parsedDownloads = (rawLogs: string) => {
   const out: { url: string, status: number, name: string }[] = [];
   for (const match of rawLogs.matchAll(DL_STAT_BLOCK)) {
-    const [, url, /* filepath */, status, /* size */, name] = match;
+    const [, url, /* filepath */, status, /* size */, /* receivedBytes */, name] = match;
     out.push({ url, status: Number.parseInt(status, 10), name: name.toLocaleLowerCase() });
   }
   return out;