diff --git a/htdocs/contact/card.php b/htdocs/contact/card.php
index f7a52afa4895d..59b5863a9ffe0 100644
--- a/htdocs/contact/card.php
+++ b/htdocs/contact/card.php
@@ -241,7 +241,7 @@
 
 		// Note: Correct date should be completed with location to have exact GM time of birth.
 		$object->birthday = dol_mktime(0, 0, 0, GETPOSTINT("birthdaymonth"), GETPOSTINT("birthdayday"), GETPOSTINT("birthdayyear"));
-		$object->birthday_alert = GETPOSTINT("birthday_alert");
+		$object->birthday_alert = (GETPOST('birthday_alert', 'alpha') == "on" ? 1 : 0);
 
 		//Default language
 		$object->default_lang = GETPOST('default_lang');
diff --git a/htdocs/contact/perso.php b/htdocs/contact/perso.php
index 0661a80b685a9..209e04d199de4 100644
--- a/htdocs/contact/perso.php
+++ b/htdocs/contact/perso.php
@@ -56,7 +56,7 @@
 
 	// Note: Correct date should be completed with location to have exact GM time of birth.
 	$object->birthday = dol_mktime(0, 0, 0, GETPOST("birthdaymonth"), GETPOST("birthdayday"), GETPOST("birthdayyear"));
-	$object->birthday_alert = GETPOSTINT("birthday_alert");
+	$object->birthday_alert = (GETPOST('birthday_alert', 'alpha') == "on" ? 1 : 0);
 
 	if (GETPOST('deletephoto')) {
 		$object->photo = '';