diff --git a/src/Endpoint.php b/src/Endpoint.php
index 8831751..46e09ff 100644
--- a/src/Endpoint.php
+++ b/src/Endpoint.php
@@ -62,6 +62,17 @@ public function __get($key)
         return $this->parameters[$key];
     }
 
+    /**
+     * Magic method to inform if specific parameter is available
+     *
+     * @param  string $key
+     * @return boolean
+     */
+    public function __isset($key)
+    {
+        return isset($this->parameters[$key]);
+    }
+
     /**
      * Check if the HTTP method is accepted and send a HTTP request to it.
      * Retrieve error from the request and throw a new error