diff --git a/digipass-class.php b/digipass-class.php
index 4cf6377..8bb5127 100755
--- a/digipass-class.php
+++ b/digipass-class.php
@@ -140,7 +140,7 @@ private static function get_blog_ids()
      */
     private static function single_activate()
     {
-        // TODO: Define activation functionality here
+        // Activation functionality
     }
 
     /**
@@ -148,7 +148,7 @@ private static function single_activate()
      */
     private static function single_deactivate()
     {
-        // TODO: Define deactivation functionality here
+        // Deactivation functionality
     }
 
     /**
diff --git a/options.php b/options.php
index 66fb385..d86cb13 100644
--- a/options.php
+++ b/options.php
@@ -11,7 +11,7 @@
 
 
 define('DP_OPTIONS', 'DP_OPTIONS');
-define('API_KEY', '31c7bc4e-90ff-44fb-9f07-b88eb06ed9dc');
+define('DP_API_KEY', '31c7bc4e-90ff-44fb-9f07-b88eb06ed9dc');
 
 
 if (is_admin()) {
@@ -186,7 +186,7 @@ function dp_page_init()
     register_setting(
         'DP_OPTIONS_GROUP', // Option group
         DP_OPTIONS, // Option name
-        'dp_sanitize' // dp_sanitize
+        'dp_sanitize' // Sanitize
     );
 
     add_settings_section(
@@ -216,7 +216,7 @@ function dp_page_init()
  */
 function dp_sanitize($input)
 {
-    $input['dp_netlicensing_apikey'] = dp_sanitize_text_field($input['dp_netlicensing_apikey']);
+    $input['dp_netlicensing_apikey'] = sanitize_text_field($input['dp_netlicensing_apikey']);
 
     return $input;
 }
diff --git a/php/curl/curl.php b/php/curl/curl.php
index 9d9497f..f3a2e1d 100755
--- a/php/curl/curl.php
+++ b/php/curl/curl.php
@@ -8,6 +8,8 @@
  * @package curl
  * @author Sean Huber <shuber@huberry.com>
 **/
+if (!class_exists('Curl')) {
+
 class Curl {
     
     /**
@@ -253,4 +255,6 @@ protected function set_request_options($url, $vars) {
         }
     }
 
-}
\ No newline at end of file
+}
+
+}
diff --git a/php/curl/curl_response.php b/php/curl/curl_response.php
index 324bafd..a52da90 100755
--- a/php/curl/curl_response.php
+++ b/php/curl/curl_response.php
@@ -7,6 +7,8 @@
  * @package curl
  * @author Sean Huber <shuber@huberry.com>
 **/
+if (!class_exists('CurlResponse')) {
+
 class CurlResponse {
     
     /**
@@ -75,4 +77,6 @@ function __toString() {
         return $this->body;
     }
     
-}
\ No newline at end of file
+}
+
+}
diff --git a/php/netlicensing/netlicensing.php b/php/netlicensing/netlicensing.php
index 2115e1f..c9d014d 100755
--- a/php/netlicensing/netlicensing.php
+++ b/php/netlicensing/netlicensing.php
@@ -6,50 +6,54 @@
  * @package netlicensing
  * @author Labs64 <info@labs64.com>
  **/
-class NetLicensing
-{
+if (!class_exists('NetLicensing')) {
 
-    const NLIC_BASE_URL = 'https://netlicensing.labs64.com/core/v2/rest';
+    class NetLicensing
+    {
 
-    private $curl = null;
+        const NLIC_BASE_URL = 'https://netlicensing.labs64.com/core/v2/rest';
 
-    /**
-     * Initializes a NetLicensing object
-     **/
-    function __construct($apiKey)
-    {
-        $user_agent = 'NetLicensing/PHP ' . PHP_VERSION . ' (http://netlicensing.labs64.com)' . '; ' . $_SERVER['HTTP_USER_AGENT'];
+        private $curl = null;
 
-        $this->curl = new Curl();
-        $this->curl->headers['Authorization'] = 'Basic ' . base64_encode("apiKey:" . $apiKey);
-        $this->curl->headers['Accept'] = 'application/json';
-        $this->curl->user_agent = $user_agent;
-    }
+        /**
+         * Initializes a NetLicensing object
+         **/
+        function __construct($apiKey)
+        {
+            $user_agent = 'NetLicensing/PHP ' . PHP_VERSION . ' (http://netlicensing.labs64.com)' . '; ' . $_SERVER['HTTP_USER_AGENT'];
 
-    /**
-     * Validates active licenses of the licensee
-     *
-     * Returns a object containing licensee validation result
-     *
-     * @param string $productNumber
-     * @param string $licenseeNumber
-     * @param string $licenseeName
-     * @return licensee validation result
-     **/
-    function validate($productNumber, $licenseeNumber, $licenseeName = '')
-    {
-        if (empty($licenseeName)) {
-            $licenseeName = $licenseeNumber;
+            $this->curl = new Curl();
+            $this->curl->headers['Authorization'] = 'Basic ' . base64_encode("apiKey:" . $apiKey);
+            $this->curl->headers['Accept'] = 'application/json';
+            $this->curl->user_agent = $user_agent;
         }
-        $params = array(
-            'productNumber' => $productNumber,
-            'name' => $licenseeName,
-        );
-        $url = self::NLIC_BASE_URL . '/licensee/' . $licenseeNumber . '/validate';
 
-        $response = $this->curl->get($url, $params);
+        /**
+         * Validates active licenses of the licensee
+         *
+         * Returns a object containing licensee validation result
+         *
+         * @param string $productNumber
+         * @param string $licenseeNumber
+         * @param string $licenseeName
+         * @return licensee validation result
+         **/
+        function validate($productNumber, $licenseeNumber, $licenseeName = '')
+        {
+            if (empty($licenseeName)) {
+                $licenseeName = $licenseeNumber;
+            }
+            $params = array(
+                'productNumber' => $productNumber,
+                'name' => $licenseeName,
+            );
+            $url = self::NLIC_BASE_URL . '/licensee/' . $licenseeNumber . '/validate';
+
+            $response = $this->curl->get($url, $params);
+
+            return $response->body;
+        }
 
-        return $response->body;
     }
 
 }