diff --git a/.travis.yml b/.travis.yml
index 406561f..05ca879 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,16 +1,15 @@
 language: php
 
 php:
-  - 5.3
-  - 5.4
-  - 5.5
   - 5.6
   - 7.0
+  - 7.1
+  - 7.2
   - hhvm
 
 matrix:
   allow_failures:
-    - php: 7.0
+    - php: 7.2
     - php: hhvm
 
 before_script:
@@ -26,4 +25,4 @@ after_failure:
   # Print *.actual content
   - 'for i in $(find ./tests -name \*.actual); do echo "--- $i"; cat $i; echo; echo; done'
 
-sudo: false
\ No newline at end of file
+sudo: false
diff --git a/composer.json b/composer.json
index ebbee46..4b2bb62 100644
--- a/composer.json
+++ b/composer.json
@@ -20,37 +20,16 @@
     "issues": "https://github.com/MetisFW/PayPal/issues"
   },
   "require": {
-    "php": ">=5.3.0",
-    "ext-curl": "*",
-    "ext-json": "*",
-    "nette/di": "~2.3@dev",
-    "nette/application": "~2.3@dev",
+    "php": ">=5.6.0",
+    "nette/di": "^2.4",
+    "nette/application": "^2.4",
     "paypal/rest-api-sdk-php": "1.5.*"
   },
   "require-dev": {
-    "nette/application": "~2.3@dev",
-    "nette/bootstrap": "~2.3@dev",
-    "nette/caching": "2.3@dev",
-    "nette/component-model": "~2.2@dev",
-    "nette/database": "~2.3@dev",
-    "nette/deprecated": "~2.3@dev",
-    "nette/di": "~2.3@dev",
-    "nette/finder": "~2.3@dev",
-    "nette/forms": "~2.3@dev",
-    "nette/http": "~2.3@dev",
-    "nette/mail": "~2.3@dev",
-    "nette/neon": "~2.3@dev",
-    "nette/php-generator": "~2.3@dev",
-    "nette/reflection": "~2.3@dev",
-    "nette/robot-loader": "~2.3@dev",
-    "nette/safe-stream": "~2.3@dev",
-    "nette/security": "~2.3@dev",
-    "nette/tokenizer": "~2.2@dev",
-    "nette/utils": "~2.3@dev",
-    "latte/latte": "~2.3@dev",
-    "tracy/tracy": "~2.3@dev",
-    "nette/tester": "@dev",
-    "mockery/mockery": "^0.9.4"
+    "nette/bootstrap": "^2.4@dev",
+    "nette/robot-loader": "^2.4@dev",
+    "nette/tester": "^1.7@dev",
+    "mockery/mockery": "^0.9@dev"
   },
   "autoload": {
     "psr-0": {
diff --git a/src/MetisFW/PayPal/Helpers/GaTracking.php b/src/MetisFW/PayPal/Helpers/GaTracking.php
index 16fe7d4..244e7d8 100644
--- a/src/MetisFW/PayPal/Helpers/GaTracking.php
+++ b/src/MetisFW/PayPal/Helpers/GaTracking.php
@@ -3,10 +3,12 @@
 namespace MetisFW\PayPal\Helpers;
 
 use Nette\Http\Url;
-use Nette\Object;
+use Nette\SmartObject;
 use PayPal\Api\Payment;
 
-class GaTracking extends Object {
+class GaTracking {
+
+  use SmartObject;
 
   private function __construct() {
     // nothing
diff --git a/src/MetisFW/PayPal/PayPalContext.php b/src/MetisFW/PayPal/PayPalContext.php
index 91a9741..e0542c2 100644
--- a/src/MetisFW/PayPal/PayPalContext.php
+++ b/src/MetisFW/PayPal/PayPalContext.php
@@ -2,10 +2,12 @@
 
 namespace MetisFW\PayPal;
 
-use Nette\Object;
+use Nette\SmartObject;
 use PayPal\Rest\ApiContext;
 
-class PayPalContext extends Object {
+class PayPalContext {
+
+  use SmartObject;
 
   /** @var ApiContext */
   private $apiContext;
diff --git a/src/MetisFW/PayPal/Payment/BasePaymentOperation.php b/src/MetisFW/PayPal/Payment/BasePaymentOperation.php
index 3d04054..4bfb7e5 100644
--- a/src/MetisFW/PayPal/Payment/BasePaymentOperation.php
+++ b/src/MetisFW/PayPal/Payment/BasePaymentOperation.php
@@ -6,7 +6,7 @@
 use MetisFW\PayPal\PayPalContext;
 use MetisFW\PayPal\PayPalException;
 use Nette\InvalidArgumentException;
-use Nette\Object;
+use Nette\SmartObject;
 use PayPal\Api\Payer;
 use PayPal\Api\Payment;
 use PayPal\Api\PaymentExecution;
@@ -16,7 +16,9 @@
 use PayPal\Exception\PayPalInvalidCredentialException;
 use PayPal\Exception\PayPalMissingCredentialException;
 
-abstract class BasePaymentOperation extends Object implements PaymentOperation {
+abstract class BasePaymentOperation implements PaymentOperation {
+
+  use SmartObject;
 
   /** @var PayPalContext */
   protected $context;
diff --git a/tests/php.ini-travis b/tests/php.ini-travis
index 50cd4a1..e225acd 100644
--- a/tests/php.ini-travis
+++ b/tests/php.ini-travis
@@ -1,4 +1,3 @@
-extension=json.so
 extension=curl.so
 extension=openssl.so
-extension=tokenizer.so
\ No newline at end of file
+extension=tokenizer.so
diff --git a/tests/php.ini-unix b/tests/php.ini-unix
index 50cd4a1..e225acd 100644
--- a/tests/php.ini-unix
+++ b/tests/php.ini-unix
@@ -1,4 +1,3 @@
-extension=json.so
 extension=curl.so
 extension=openssl.so
-extension=tokenizer.so
\ No newline at end of file
+extension=tokenizer.so