diff --git a/src/Mailjet/php-mailjet-v3-simple.class.php b/src/Mailjet/php-mailjet-v3-simple.class.php
index 976f6b1..8e362e5 100644
--- a/src/Mailjet/php-mailjet-v3-simple.class.php
+++ b/src/Mailjet/php-mailjet-v3-simple.class.php
@@ -251,7 +251,7 @@ public function requestUrlBuilder($resource, $params = array(), $request, $id)
         if ($resource == "sendEmail") {
             $this->call_url = $this->apiUrl."/send/message";
         }
-	else if ($resource == "send") { 
+	else if ($resource == "send") {
             $this->call_url = $this->apiUrl."/send";  	//json support for SendAPI
         }
         else if ($resource == "uploadCSVContactslistData") {
@@ -278,7 +278,7 @@ public function requestUrlBuilder($resource, $params = array(), $request, $id)
         }
         else if (in_array($resource, self::$_templateResources))
         {
-            $this->call_url = $this->makeUrlFromFilter('REST', 'template', $params['ID'], $resource);         
+            $this->call_url = $this->makeUrlFromFilter('REST', 'template', $params['ID'], $resource);
         }
         else if (in_array($resource, self::$_contactResources))
         {
@@ -407,8 +407,15 @@ public function sendRequest($resource = false, $params = array(), $request = "GE
                     unset($params['ID']);
                 }
 
-		// 64 => unescaped_slashes
-                curl_setopt($curl_handle, CURLOPT_POSTFIELDS, json_encode($params, 64));
+                $j_e = null;
+                if (version_compare(phpversion(), '5.4.0', '<')) {
+                    $j_e = str_replace('\\/', '/', json_encode($params));
+                } else {
+					// 64 => unescaped_slashes
+                    $j_e = json_encode($params, 64);
+                }
+
+                curl_setopt($curl_handle, CURLOPT_POSTFIELDS, $j_e);
                 curl_setopt($curl_handle, CURLOPT_HTTPHEADER, array(
                     'Content-Type: application/json'
                 ));