diff --git a/src/Responder.php b/src/Responder.php
index 15146e4..972095f 100644
--- a/src/Responder.php
+++ b/src/Responder.php
@@ -8,6 +8,7 @@
 use Amp\ByteStream\StreamException;
 use Amp\Deferred;
 use Amp\Socket\Socket;
+use Error;
 use Ostrolucky\Stdinho\Bufferer\AbstractBufferer;
 use Psr\Log\LoggerInterface;
 use Symfony\Component\Console\Output\ConsoleOutput;
@@ -76,7 +77,11 @@ public function __invoke(Socket $socket): \Generator
 
         // Only at this point it's safe to resolve the promise, otherwise Responder
         // would think everything was buffered and specify wrong content length!
-        $this->defererThatIsResolvedWhenSomebodyConnects->resolve();
+        try {
+            $this->defererThatIsResolvedWhenSomebodyConnects->resolve();
+        } catch (Error $e) {
+            // Promise might have been already resolved
+        }
 
         $progressBar = new ProgressBar(
             $this->consoleOutput->section(),
@@ -87,43 +92,7 @@ public function __invoke(Socket $socket): \Generator
 
         try {
             yield $socket->write(implode("\r\n", array_merge($header, $this->customHttpHeaders))."\r\n\r\n");
-
-            while (true) {
-                $buffererProgress = $this->bufferer->getCurrentProgress();
-
-                /**
-                 * Not trying to read the buffer when connected client caught up to it is important for following:
-                 *
-                 * 1. Reduce CPU usage and potential block operations thanks to avoiding executing logic in read()
-                 * 2. Prevent ResourceInputStream to close the resource when it detects feof. This serves as workaround.
-                 *
-                 * @see https://github.com/ostrolucky/stdinho/pull/2
-                 * @see https://github.com/amphp/byte-stream/issues/47
-                 */
-                if ($buffererProgress <= $progressBar->step && $this->bufferer->isBuffering()) {
-                    yield $this->bufferer->waitForWrite();
-
-                    continue;
-                }
-
-                if (null !== $chunk = yield $this->inputStream->read()) {
-                    yield $socket->write($chunk);
-
-                    $progressBar->max = $this->bufferer->getCurrentProgress();
-                    $progressBar->advance(strlen($chunk));
-
-                    continue;
-                }
-
-                if (!$this->bufferer->inputStream) {
-                    break; // All input sources depleted -> finish download
-                }
-
-                // Use fallback inputStream - handy when PipeBufferer exits sooner than it consumes its inputStream
-                $this->inputStream = $this->bufferer->inputStream;
-                // Prevent other potential Responders to consume same inputStream. This can be solved in future
-                $this->bufferer->inputStream = null;
-            }
+            yield from $this->write($socket, $progressBar);
             $progressBar->finish();
             $this->logger->debug("$remoteAddress finished download");
         } catch (StreamException $exception) {
@@ -132,4 +101,44 @@ public function __invoke(Socket $socket): \Generator
 
         $socket->end();
     }
+
+    private function write(Socket $socket, ProgressBar $progressBar): \Generator
+    {
+        while (true) {
+            $buffererProgress = $this->bufferer->getCurrentProgress();
+
+            /**
+             * Not trying to read the buffer when connected client caught up to it is important for following:
+             *
+             * 1. Reduce CPU usage and potential block operations thanks to avoiding executing logic in read()
+             * 2. Prevent ResourceInputStream to close the resource when it detects feof. This serves as workaround.
+             *
+             * @see https://github.com/ostrolucky/stdinho/pull/2
+             * @see https://github.com/amphp/byte-stream/issues/47
+             */
+            if ($buffererProgress <= $progressBar->step && $this->bufferer->isBuffering()) {
+                yield $this->bufferer->waitForWrite();
+
+                continue;
+            }
+
+            if (null !== $chunk = yield $this->inputStream->read()) {
+                yield $socket->write($chunk);
+
+                $progressBar->max = $this->bufferer->getCurrentProgress();
+                $progressBar->advance(strlen($chunk));
+
+                continue;
+            }
+
+            if (!$this->bufferer->inputStream) {
+                break; // All input sources depleted -> finish download
+            }
+
+            // Use fallback inputStream - handy when PipeBufferer exits sooner than it consumes its inputStream
+            $this->inputStream = $this->bufferer->inputStream;
+            // Prevent other potential Responders to consume same inputStream. This can be solved in future
+            $this->bufferer->inputStream = null;
+        }
+    }
 }