diff --git a/README.md b/README.md
index 51bbef1e..d705193f 100644
--- a/README.md
+++ b/README.md
@@ -118,8 +118,8 @@ $server->on('error', function (Exception $e) {
 ```
 
 The server will also emit an `error` event if you return an invalid
-type in the callback function or have a unhandled `Exception`.
-If your callback function throws an exception,
+type in the callback function or have a unhandled `Exception` or `Throwable`.
+If your callback function throws an `Exception` or `Throwable`,
 the `Server` will emit a `RuntimeException` and add the thrown exception
 as previous:
 
@@ -540,9 +540,9 @@ $server = new Server(function (ServerRequestInterface $request) use ($stream) {
 });
 ```
 
-An invalid return value or an unhandled `Exception` in the code of the callback
-function, will result in an `500 Internal Server Error` message.
-Make sure to catch `Exceptions` to create own response messages.
+An invalid return value or an unhandled `Exception` or `Throwable` in the code
+of the callback function, will result in an `500 Internal Server Error` message.
+Make sure to catch `Exceptions` or `Throwables` to create own response messages.
 
 After the return in the callback function the response will be processed by the `Server`.
 The `Server` will add the protocol version of the request, so you don't have to.
diff --git a/composer.json b/composer.json
index e73e29c7..e040c784 100644
--- a/composer.json
+++ b/composer.json
@@ -8,7 +8,7 @@
         "ringcentral/psr7": "^1.2",
         "react/socket": "^1.0 || ^0.8 || ^0.7 || ^0.6 || ^0.5",
         "react/stream": "^1.0 || ^0.7 || ^0.6 || ^0.5 || ^0.4.6",
-        "react/promise": "^2.1 || ^1.2.1",
+        "react/promise": "^2.3 || ^1.2.1",
         "evenement/evenement": "^2.0 || ^1.0"
     },
     "autoload": {
diff --git a/src/Server.php b/src/Server.php
index 6f9236e4..aebc9c8e 100644
--- a/src/Server.php
+++ b/src/Server.php
@@ -257,7 +257,14 @@ function ($response) use ($that, $conn, $request) {
             function ($error) use ($that, $conn, $request) {
                 $message = 'The response callback is expected to resolve with an object implementing Psr\Http\Message\ResponseInterface, but rejected with "%s" instead.';
                 $message = sprintf($message, is_object($error) ? get_class($error) : gettype($error));
-                $exception = new \RuntimeException($message, null, $error instanceof \Exception ? $error : null);
+
+                $previous = null;
+
+                if ($error instanceof \Throwable || $error instanceof \Exception) {
+                    $previous = $error;
+                }
+
+                $exception = new \RuntimeException($message, null, $previous);
 
                 $that->emit('error', array($exception));
                 return $that->writeError($conn, 500, $request);
diff --git a/tests/ServerTest.php b/tests/ServerTest.php
index 61ef1fbd..4ea1722a 100644
--- a/tests/ServerTest.php
+++ b/tests/ServerTest.php
@@ -2805,6 +2805,52 @@ function ($data) use (&$buffer) {
         $this->assertEquals('hello', $exception->getPrevious()->getMessage());
     }
 
+    /**
+     * @requires PHP 7
+     */
+    public function testThrowableThrowInCallBackFunctionWillResultInErrorMessage()
+    {
+        $server = new Server(function (ServerRequestInterface $request) {
+            throw new \Error('hello');
+        });
+
+        $exception = null;
+        $server->on('error', function (\Exception $ex) use (&$exception) {
+            $exception = $ex;
+        });
+
+        $buffer = '';
+        $this->connection
+            ->expects($this->any())
+            ->method('write')
+            ->will(
+                $this->returnCallback(
+                    function ($data) use (&$buffer) {
+                        $buffer .= $data;
+                    }
+                )
+            );
+
+        $server->listen($this->socket);
+        $this->socket->emit('connection', array($this->connection));
+
+        $data = $this->createGetRequest();
+
+        try {
+            $this->connection->emit('data', array($data));
+        } catch (\Error $e) {
+            $this->markTestSkipped(
+                'A \Throwable bubbled out of the request callback. ' .
+                'This happened most probably due to react/promise:^1.0 being installed ' .
+                'which does not support \Throwable.'
+            );
+        }
+
+        $this->assertInstanceOf('RuntimeException', $exception);
+        $this->assertContains("HTTP/1.1 500 Internal Server Error\r\n", $buffer);
+        $this->assertEquals('hello', $exception->getPrevious()->getMessage());
+    }
+
     public function testRejectOfNonExceptionWillResultInErrorMessage()
     {
         $server = new Server(function (ServerRequestInterface $request) {