diff --git a/QuickPay/API/Response.php b/QuickPay/API/Response.php
index e7dbad2..167c195 100644
--- a/QuickPay/API/Response.php
+++ b/QuickPay/API/Response.php
@@ -82,13 +82,14 @@ public function as_raw($keep_authorization_value = false)
             $sent_headers = implode("\n", $lines);
         }
 
-        return [
+        return array(
             $this->status_code,
-            ['sent' => $sent_headers,
-             'received' => $this->received_headers,
-            ],
+            array(
+                'sent' => $sent_headers,
+                'received' => $this->received_headers,
+            ),
             $this->response_data,
-        ];
+        );
     }
 
     /**
diff --git a/composer.json b/composer.json
index 9c3ea60..50f9729 100644
--- a/composer.json
+++ b/composer.json
@@ -5,6 +5,7 @@
     "homepage": "https://github.com/QuickPay/quickpay-php-client",
     "license": "MIT",
     "require": {
+        "php": ">=5.3.3",
         "lib/curl": "dev-master"
     },
     "require-dev" : {
@@ -16,4 +17,4 @@
             "QuickPay\\": "QuickPay/"
         }
     }
-}
\ No newline at end of file
+}