diff --git a/README.md b/README.md
index d1a8e3d..e1106b6 100644
--- a/README.md
+++ b/README.md
@@ -44,7 +44,7 @@ $gateway = Omnipay::create('Sberbank');
 $gateway->authorize(
     [
        'orderNumber' => $localOrderNumber, // local order number
-       'amount' => $order_amount * 100, // The amount of payment in kopecks (or cents)
+       'amount' => $order_amount, // The amount of payment (you can use integer, decimal with 2 precisions or string equal to decimal
        'returnUrl' => $callback_url // succesfull callback url
     ]
 );
@@ -113,7 +113,7 @@ $gateway = Omnipay::create('Sberbank');
 $response = $gateway->authorize(
     [
        'orderNumber' => $localOrderNumber, // local order number
-       'amount' => $order_amount * 100, // The amount of payment in kopecks (or cents)
+       'amount' => $order_amount, // The amount of payment (you can use integer, decimal with 2 precisions or string equal to decimal
        'returnUrl' => $callback_url, // succesfull callback url
        'description' => 'Order Description'
     ]
@@ -161,7 +161,7 @@ $gateway = Omnipay::create('Sberbank');
 $response = $gateway->authorize(
     [
        'orderNumber' => $localOrderNumber, // local order number
-       'amount' => $order_amount * 100, // The amount of payment in kopecks (or cents)
+       'amount' => $order_amount, // The amount of payment (you can use integer, decimal with 2 precisions or string equal to decimal
        'returnUrl' => $callback_url, // succesfull callback url
        'description' => 'Order Description'
     ]
@@ -210,7 +210,7 @@ $gateway = Omnipay::create('Sberbank');
 $response = $gateway->capture(
     [
        'orderId' => $localOrderNumber, // gateway order number
-       'amount' => $order_amount * 100, // The amount of payment in kopecks (or cents)
+       'amount' => $order_amount, // The amount of payment (you can use integer, decimal with 2 precisions or string equal to decimal
     ]
 )->setUserName('merchant_login')
  ->setPassword('merchant_password')
diff --git a/composer.json b/composer.json
index 428b6d1..5995210 100644
--- a/composer.json
+++ b/composer.json
@@ -32,7 +32,7 @@
   },
   "autoload-dev": {
     "psr-4": {
-      "Tests\\Examples\\": "tests/Examples"
+      "Omnipay\\Sberbank\\Tests\\": "tests/"
     }
   },
   "minimum-stability": "dev",
diff --git a/src/Message/AbstractRequest.php b/src/Message/AbstractRequest.php
index d04af12..415ab03 100644
--- a/src/Message/AbstractRequest.php
+++ b/src/Message/AbstractRequest.php
@@ -155,14 +155,19 @@ public function sendData($data)
     {
         $url = $this->getEndPoint() . $this->getMethod();
         $this->validate('userName', 'password');
+        $data = array_merge(
+            [
+                'userName' => $this->getUserName(),
+                'password' => $this->getPassword(),
+            ],
+            $data
+        );
+
         $httpResponse = $this->httpClient->request(
             $this->getHttpMethod(),
             $url,
             $this->getHeaders(),
-            json_encode(array_merge([
-                'userName' => $this->getUserName(),
-                'password' => $this->getPassword()
-            ], $data))
+            http_build_query($data, '', '&')
         );
 
         $responseClassName = str_replace('Request', 'Response', \get_class($this));
@@ -173,7 +178,9 @@ public function sendData($data)
             );
         }
 
-        return $reflection->newInstance($this, json_decode($httpResponse->getBody(), true));
+        $content = json_decode($httpResponse->getBody()->getContents(), true);
+
+        return $reflection->newInstance($this, $content);
     }
 
     /**
diff --git a/src/Message/AuthorizeRequest.php b/src/Message/AuthorizeRequest.php
index 57ef5dc..0f7e5c0 100644
--- a/src/Message/AuthorizeRequest.php
+++ b/src/Message/AuthorizeRequest.php
@@ -241,14 +241,19 @@ public function sendData($data)
         $this->validate('userName', 'password');
         $data['currency'] = $this->getCurrencyNumeric();
         $data['amount'] = $this->getAmountInteger();
+        $data = array_merge(
+            [
+                'userName' => $this->getUserName(),
+                'password' => $this->getPassword(),
+            ],
+            $data
+        );
+
         $httpResponse = $this->httpClient->request(
             $this->getHttpMethod(),
             $url,
             $this->getHeaders(),
-            json_encode(array_merge([
-                'userName' => $this->getUserName(),
-                'password' => $this->getPassword()
-            ], $data))
+            http_build_query($data, '', '&')
         );
 
         $responseClassName = str_replace('Request', 'Response', \get_class($this));
@@ -259,6 +264,8 @@ public function sendData($data)
             );
         }
 
-        return $reflection->newInstance($this, json_decode($httpResponse->getBody(true), true));
+        $content = json_decode($httpResponse->getBody()->getContents(), true);
+
+        return $reflection->newInstance($this, $content);
     }
 }
diff --git a/src/Message/CaptureRequest.php b/src/Message/CaptureRequest.php
index f1b128e..60bbb6d 100644
--- a/src/Message/CaptureRequest.php
+++ b/src/Message/CaptureRequest.php
@@ -18,7 +18,7 @@ public function getData()
 
         $data = [
             'orderId' => $this->getOrderId(),
-            'amount' => $this->getAmount(),
+            'amount' => $this->getAmountInteger(),
         ];
 
         return $data;
diff --git a/src/Message/RefundRequest.php b/src/Message/RefundRequest.php
index 7b68c60..1eddf09 100644
--- a/src/Message/RefundRequest.php
+++ b/src/Message/RefundRequest.php
@@ -18,7 +18,7 @@ public function getData()
 
         $data = [
             'orderId' => $this->getOrderId(),
-            'amount' => $this->getAmount(),
+            'amount' => $this->getAmountInteger(),
         ];
 
         return $data;
diff --git a/tests/Message/CaptureRequestTest.php b/tests/Message/CaptureRequestTest.php
index 6096525..444096e 100644
--- a/tests/Message/CaptureRequestTest.php
+++ b/tests/Message/CaptureRequestTest.php
@@ -69,7 +69,9 @@ protected function getRequestParameters()
      */
     public function testData()
     {
-        $this->assertEquals($this->request->getData(), $this->getRequestParameters());
+        $params = $this->getRequestParameters();
+        $params['amount'] = $params['amount'] * 100;
+        $this->assertEquals($this->request->getData(), $params);
     }
 
     /**
diff --git a/tests/Message/RefundRequestTest.php b/tests/Message/RefundRequestTest.php
index 19e922c..2c23980 100644
--- a/tests/Message/RefundRequestTest.php
+++ b/tests/Message/RefundRequestTest.php
@@ -74,7 +74,9 @@ public function getMethod()
      */
     public function testData()
     {
-        $this->assertEquals($this->request->getData(), $this->getRequestParameters());
+        $params = $this->getRequestParameters();
+        $params['amount'] = $params['amount'] * 100;
+        $this->assertEquals($this->request->getData(), $params);
     }
 
     /**