diff --git a/JsonRpc2/Controller.php b/JsonRpc2/Controller.php
index 85dd0dc..335b36f 100644
--- a/JsonRpc2/Controller.php
+++ b/JsonRpc2/Controller.php
@@ -56,7 +56,7 @@ public function runAction($id, $params = [])
 
         $response = new Response();
         $response->format = Response::FORMAT_JSON;
-        $response->data = $isBatch ? $resultData : current($resultData);
+        $response->data = $isBatch || null === $resultData ? $resultData : current($resultData);
         return $response;
     }
 
@@ -69,7 +69,7 @@ public function runAction($id, $params = [])
      */
     private function getActionResponse($requestObject)
     {
-        $result = $error = null;
+        $this->requestObject = $result = $error = null;
         try {
             $this->parseAndValidateRequestObject($requestObject);
             ob_start();
@@ -84,7 +84,7 @@ private function getActionResponse($requestObject)
             $error = new Exception("Internal error", Exception::INTERNAL_ERROR);
         }
 
-        if (!isset($this->requestObject->id) && (empty($error) || $error->getCode() != Exception::PARSE_ERROR))
+        if (!isset($this->requestObject->id) && (empty($error) || !in_array($error->getCode(), [Exception::PARSE_ERROR, Exception::INVALID_REQUEST])))
             return null;
 
         return Helper::formatResponse($result, $error, !empty($this->requestObject->id)? $this->requestObject->id : null);
@@ -192,13 +192,18 @@ private function initRequest($id)
      */
     private function parseAndValidateRequestObject($requestObject)
     {
-        if (!is_object($requestObject))
+        if (null === $requestObject)
             throw new Exception("Parse error", Exception::PARSE_ERROR);
 
-        if (!isset($requestObject->jsonrpc) || $requestObject->jsonrpc !== '2.0' || empty($requestObject->method))
+        if (!is_object($requestObject)
+            || !isset($requestObject->jsonrpc) || $requestObject->jsonrpc !== '2.0'
+            || empty($requestObject->method) || "string" != gettype($requestObject->method)
+        )
             throw new Exception("Invalid Request", Exception::INVALID_REQUEST);
 
         $this->requestObject = $requestObject;
+        if (!isset($this->requestObject->params))
+            $this->requestObject->params = [];
     }
 
     /**
diff --git a/JsonRpc2/Helper.php b/JsonRpc2/Helper.php
index 74b311c..2fc190d 100644
--- a/JsonRpc2/Helper.php
+++ b/JsonRpc2/Helper.php
@@ -18,19 +18,22 @@ class Helper
      */
     public static function formatResponse ($result = null, Exception $error = null, $id = null)
     {
-        $response = [
-            'jsonrpc' => '2.0',
-            'id' => $id,
-        ];
+        $resultKey = 'result';
 
-        if (!empty($error))
-            $response['error'] = $error->toArray();
+        if (!empty($error)) {
+            $resultKey = 'error';
+            $resultValue = $error->toArray();
+        }
         else if (null === $result)
-            $response['result'] = self::$defaultResult;
+            $resultValue = self::$defaultResult;
         else
-            $response['result'] = $result;
+            $resultValue = $result;
 
-        return $response;
+        return [
+            'jsonrpc' => '2.0',
+            $resultKey => $resultValue,
+            'id' => $id,
+        ];
     }
 
     /**