diff --git a/src/main/php/web/handler/FilesFrom.class.php b/src/main/php/web/handler/FilesFrom.class.php
index 07baac45..96e80e8b 100755
--- a/src/main/php/web/handler/FilesFrom.class.php
+++ b/src/main/php/web/handler/FilesFrom.class.php
@@ -6,7 +6,8 @@
 use web\io\Ranges;
 
 class FilesFrom implements Handler {
-  const BOUNDARY = '594fa07300f865fe';
+  const BOUNDARY  = '594fa07300f865fe';
+  const CHUNKSIZE = 8192;
 
   private $path;
 
@@ -45,7 +46,7 @@ public function handle($request, $response) {
       $file= $target->asFile();
     }
 
-    $this->serve($request, $response, $file);
+    return $this->serve($request, $response, $file);
   }
 
   /**
@@ -53,12 +54,17 @@ public function handle($request, $response) {
    *
    * @param  web.io.Output $output
    * @param  io.File $file
-   * @param  int $length
+   * @param  web.io.Range $range
+   * @return iterable
    */
-  private function copy($output, $file, $length) {
-    while ($length && $chunk= $file->read(min(8192, $length))) {
+  private function copy($output, $file, $range) {
+    $file->seek($range->start());
+
+    $length= $range->length();
+    while ($length && $chunk= $file->read(min(self::CHUNKSIZE, $length))) {
       $output->write($chunk);
       $length-= strlen($chunk);
+      yield;
     }
   }
 
@@ -94,7 +100,19 @@ public function serve($request, $response, $target) {
     $mimeType= MimeType::getByFileName($file->filename);
     if (null === ($ranges= Ranges::in($request->header('Range'), $file->size()))) {
       $response->answer(200, 'OK');
-      $response->transfer($file->in(), $mimeType, $file->size());
+      $response->header('Content-Type', $mimeType);
+
+      $out= $response->stream($file->size());
+      $file->open(File::READ);
+      try {
+        do {
+          $out->write($file->read(self::CHUNKSIZE));
+          yield;
+        } while (!$file->eof());
+      } finally {
+        $file->close();
+        $out->close();
+      }
       return;
     }
 
@@ -106,47 +124,41 @@ public function serve($request, $response, $target) {
     }
 
     $file->open(File::READ);
-    $output= $response->output();
     $response->answer(206, 'Partial Content');
 
     try {
       if ($range= $ranges->single()) {
         $response->header('Content-Type', $mimeType);
         $response->header('Content-Range', $ranges->format($range));
-        $response->header('Content-Length', $range->length());
 
-        $file->seek($range->start());
-        $response->flush();
-        $this->copy($output, $file, $range->length());
+        $out= $response->stream($range->length());
+        yield from $this->copy($out, $file, $range);
       } else {
         $headers= [];
         $trailer= "\r\n--".self::BOUNDARY."--\r\n";
-
         $length= strlen($trailer);
+
         foreach ($ranges->sets() as $i => $range) {
-          $header= sprintf(
+          $headers[$i]= $header= sprintf(
             "\r\n--%s\r\nContent-Type: %s\r\nContent-Range: %s\r\n\r\n",
             self::BOUNDARY,
             $mimeType,
             $ranges->format($range)
           );
-          $headers[$i]= $header;
           $length+= strlen($header) + $range->length();
         }
-
         $response->header('Content-Type', 'multipart/byteranges; boundary='.self::BOUNDARY);
-        $response->header('Content-Length', $length);
-        $response->flush();
+
+        $out= $response->stream($length);
         foreach ($ranges->sets() as $i => $range) {
-          $output->write($headers[$i]);
-          $file->seek($range->start());
-          $this->copy($output, $file, $range->length());
+          $out->write($headers[$i]);
+          yield from $this->copy($out, $file, $range);
         }
-        $output->write($trailer);
+        $out->write($trailer);
       }
     } finally {
       $file->close();
-      $output->close();
+      $out->close();
     }
   }
 }
\ No newline at end of file
diff --git a/src/test/php/web/unittest/handler/FilesFromTest.class.php b/src/test/php/web/unittest/handler/FilesFromTest.class.php
index 9590db01..5e5874ba 100755
--- a/src/test/php/web/unittest/handler/FilesFromTest.class.php
+++ b/src/test/php/web/unittest/handler/FilesFromTest.class.php
@@ -56,6 +56,24 @@ private function assertResponse($expected, $response) {
     ));
   }
 
+  /**
+   * Returns
+   *
+   * @param  web.handler.FilesFrom $files
+   * @param  web.Request $req
+   * @return web.Response
+   */
+  private function handle($files, $req) {
+    $res= new Response(new TestOutput());
+
+    try {
+      foreach ($files->handle($req, $res) ?? [] as $_) { }
+      return $res;
+    } finally {
+      $res->end();
+    }
+  }
+
   /** @return void */
   public function tearDown() {
     foreach ($this->cleanup as $folder) {
@@ -70,12 +88,7 @@ public function can_create() {
 
   #[Test]
   public function existing_file() {
-    $req= new Request(new TestInput('GET', '/test.html'));
-    $res= new Response(new TestOutput());
-
-    $files= (new FilesFrom($this->pathWith(['test.html' => 'Test'])));
-    $files->handle($req, $res);
-
+    $files= new FilesFrom($this->pathWith(['test.html' => 'Test']));
     $this->assertResponse(
       "HTTP/1.1 200 OK\r\n".
       "Accept-Ranges: bytes\r\n".
@@ -85,33 +98,25 @@ public function existing_file() {
       "Content-Length: 4\r\n".
       "\r\n".
       "Test",
-      $res
+      $this->handle($files, new Request(new TestInput('GET', '/test.html')))
     );
   }
 
   #[Test]
   public function existing_file_unmodified_since() {
-    $req= new Request(new TestInput('GET', '/test.html', ['If-Modified-Since' => gmdate('D, d M Y H:i:s T', time() + 1)]));
-    $res= new Response(new TestOutput()); 
-
-    $files= (new FilesFrom($this->pathWith(['test.html' => 'Test'])));
-    $files->handle($req, $res);
-
+    $files= new FilesFrom($this->pathWith(['test.html' => 'Test']));
     $this->assertResponse(
       "HTTP/1.1 304 Not Modified\r\n".
       "\r\n",
-      $res
+      $this->handle($files, new Request(new TestInput('GET', '/test.html', [
+        'If-Modified-Since' => gmdate('D, d M Y H:i:s T', time() + 1)
+      ])))
     );
   }
 
   #[Test]
   public function index_html() {
-    $req= new Request(new TestInput('GET', '/'));
-    $res= new Response(new TestOutput());
-
-    $files= (new FilesFrom($this->pathWith(['index.html' => 'Home'])));
-    $files->handle($req, $res);
-
+    $files= new FilesFrom($this->pathWith(['index.html' => 'Home']));
     $this->assertResponse(
       "HTTP/1.1 200 OK\r\n".
       "Accept-Ranges: bytes\r\n".
@@ -121,89 +126,63 @@ public function index_html() {
       "Content-Length: 4\r\n".
       "\r\n".
       "Home",
-      $res
+      $this->handle($files, new Request(new TestInput('GET', '/')))
     );
   }
 
   #[Test]
   public function redirect_if_trailing_slash_missing() {
-    $req= new Request(new TestInput('GET', '/preview'));
-    $res= new Response(new TestOutput());
-
-    $files= (new FilesFrom($this->pathWith(['preview' => ['index.html' => 'Home']])));
-    $files->handle($req, $res);
-
+    $files= new FilesFrom($this->pathWith(['preview' => ['index.html' => 'Home']]));
     $this->assertResponse(
       "HTTP/1.1 301 Moved Permanently\r\n".
       "Location: preview/\r\n".
       "\r\n",
-      $res
+      $this->handle($files, new Request(new TestInput('GET', '/preview')))
     );
   }
 
   #[Test]
   public function non_existant_file() {
-    $req= new Request(new TestInput('GET', '/test.html'));
-    $res= new Response(new TestOutput());
-
-    $files= (new FilesFrom($this->pathWith([])));
-    $files->handle($req, $res);
-
+    $files= new FilesFrom($this->pathWith([]));
     $this->assertResponse(
       "HTTP/1.1 404 Not Found\r\n".
       "Content-Type: text/plain\r\n".
       "Content-Length: 35\r\n".
       "\r\n".
       "The file '/test.html' was not found",
-      $res
+      $this->handle($files, new Request(new TestInput('GET', '/test.html')))
     );
   }
 
   #[Test]
   public function non_existant_index_html() {
-    $req= new Request(new TestInput('GET', '/'));
-    $res= new Response(new TestOutput());
-
-    $files= (new FilesFrom($this->pathWith([])));
-    $files->handle($req, $res);
-
+    $files= new FilesFrom($this->pathWith([]));
     $this->assertResponse(
       "HTTP/1.1 404 Not Found\r\n".
       "Content-Type: text/plain\r\n".
       "Content-Length: 26\r\n".
       "\r\n".
       "The file '/' was not found",
-      $res
+      $this->handle($files, new Request(new TestInput('GET', '/')))
     );
   }
 
   #[Test, Values(['/../credentials', '/static/../../credentials'])]
   public function cannot_access_below_path_root($uri) {
-    $req= new Request(new TestInput('GET', $uri));
-    $res= new Response(new TestOutput());
-
-    $path= $this->pathWith(['credentials' => 'secret']);
-    $files= new FilesFrom(new Folder($path, 'webroot'));
-    $files->handle($req, $res);
-
+    $files= new FilesFrom(new Folder($this->pathWith(['credentials' => 'secret']), 'webroot'));
     $this->assertResponse(
       "HTTP/1.1 404 Not Found\r\n".
       "Content-Type: text/plain\r\n".
       "Content-Length: 37\r\n".
       "\r\n".
       "The file '/credentials' was not found",
-      $res
+      $this->handle($files, new Request(new TestInput('GET', $uri)))
     );
   }
 
   #[Test, Values([['0-3', 'Home'], ['4-7', 'page'], ['0-0', 'H'], ['4-4', 'p'], ['7-7', 'e']])]
   public function range_with_start_and_end($range, $result) {
-    $req= new Request(new TestInput('GET', '/', ['Range' => 'bytes='.$range]));
-    $res= new Response(new TestOutput());
-
-    $files= (new FilesFrom($this->pathWith(['index.html' => 'Homepage'])));
-    $files->handle($req, $res);
-
+    $files= new FilesFrom($this->pathWith(['index.html' => 'Homepage']));
     $this->assertResponse(
       "HTTP/1.1 206 Partial Content\r\n".
       "Accept-Ranges: bytes\r\n".
@@ -214,18 +193,13 @@ public function range_with_start_and_end($range, $result) {
       "Content-Length: ".strlen($result)."\r\n".
       "\r\n".
       $result,
-      $res
+      $this->handle($files, new Request(new TestInput('GET', '/', ['Range' => 'bytes='.$range])))
     );
   }
 
   #[Test]
   public function range_from_offset_until_end() {
-    $req= new Request(new TestInput('GET', '/', ['Range' => 'bytes=4-']));
-    $res= new Response(new TestOutput());
-
-    $files= (new FilesFrom($this->pathWith(['index.html' => 'Homepage'])));
-    $files->handle($req, $res);
-
+    $files= new FilesFrom($this->pathWith(['index.html' => 'Homepage']));
     $this->assertResponse(
       "HTTP/1.1 206 Partial Content\r\n".
       "Accept-Ranges: bytes\r\n".
@@ -236,18 +210,13 @@ public function range_from_offset_until_end() {
       "Content-Length: 4\r\n".
       "\r\n".
       "page",
-      $res
+      $this->handle($files, new Request(new TestInput('GET', '/', ['Range' => 'bytes=4-'])))
     );
   }
 
   #[Test, Values([0, 8192, 10000])]
   public function range_last_four_bytes($offset) {
-    $req= new Request(new TestInput('GET', '/', ['Range' => 'bytes=-4']));
-    $res= new Response(new TestOutput());
-
-    $files= (new FilesFrom($this->pathWith(['index.html' => str_repeat('*', $offset).'Homepage'])));
-    $files->handle($req, $res);
-
+    $files= new FilesFrom($this->pathWith(['index.html' => str_repeat('*', $offset).'Homepage']));
     $this->assertResponse(
       "HTTP/1.1 206 Partial Content\r\n".
       "Accept-Ranges: bytes\r\n".
@@ -258,18 +227,13 @@ public function range_last_four_bytes($offset) {
       "Content-Length: 4\r\n".
       "\r\n".
       "page",
-      $res
+      $this->handle($files, new Request(new TestInput('GET', '/', ['Range' => 'bytes=-4'])))
     );
   }
 
   #[Test, Values(['bytes=0-2000', 'bytes=4-2000', 'bytes=2000-', 'bytes=2000-2001', 'bytes=2000-0', 'bytes=4-0', 'characters=0-'])]
   public function range_unsatisfiable($range) {
-    $req= new Request(new TestInput('GET', '/', ['Range' => $range]));
-    $res= new Response(new TestOutput());
-
-    $files= (new FilesFrom($this->pathWith(['index.html' => 'Homepage'])));
-    $files->handle($req, $res);
-
+    $files= new FilesFrom($this->pathWith(['index.html' => 'Homepage']));
     $this->assertResponse(
       "HTTP/1.1 416 Range Not Satisfiable\r\n".
       "Accept-Ranges: bytes\r\n".
@@ -277,18 +241,13 @@ public function range_unsatisfiable($range) {
       "X-Content-Type-Options: nosniff\r\n".
       "Content-Range: bytes */8\r\n".
       "\r\n",
-      $res
+      $this->handle($files, new Request(new TestInput('GET', '/', ['Range' => $range])))
     );
   }
 
   #[Test]
   public function multi_range() {
-    $req= new Request(new TestInput('GET', '/', ['Range' => 'bytes=0-3,4-7']));
-    $res= new Response(new TestOutput());
-
-    $files= (new FilesFrom($this->pathWith(['index.html' => 'Homepage'])));
-    $files->handle($req, $res);
-
+    $files= new FilesFrom($this->pathWith(['index.html' => 'Homepage']));
     $this->assertResponse(
       "HTTP/1.1 206 Partial Content\r\n".
       "Accept-Ranges: bytes\r\n".
@@ -306,7 +265,7 @@ public function multi_range() {
       "Content-Range: bytes 4-7/8\r\n\r\n".
       "page".
       "\r\n--594fa07300f865fe--\r\n",
-      $res
+      $this->handle($files, new Request(new TestInput('GET', '/', ['Range' => 'bytes=0-3,4-7'])))
     );
   }
 }
\ No newline at end of file