diff --git a/htdocs/core/modules/security/captcha/modCaptchaStandard.class.php b/htdocs/core/modules/security/captcha/modCaptchaStandard.class.php
index 6b22ec7c1da..0efb00838b0 100644
--- a/htdocs/core/modules/security/captcha/modCaptchaStandard.class.php
+++ b/htdocs/core/modules/security/captcha/modCaptchaStandard.class.php
@@ -53,7 +53,7 @@ class modCaptchaStandard extends ModeleCaptcha
 	 */
 	public function __construct($db, $conf, $langs, $user)
 	{
-		$this->id = strtolower(preg_replace('/^modCaptcha/i', '', get_class()));
+		$this->id = strtolower(preg_replace('/^modCaptcha/i', '', get_class($this)));
 
 		$this->db = $db;
 		$this->conf = $conf;