diff --git a/htdocs/contact/class/contact.class.php b/htdocs/contact/class/contact.class.php
index 9cb5f4a7867..2034803ecb8 100644
--- a/htdocs/contact/class/contact.class.php
+++ b/htdocs/contact/class/contact.class.php
@@ -353,9 +353,9 @@ class Contact extends CommonObject
 		// Clean parameters
 		$this->lastname = $this->lastname ?trim($this->lastname) : trim($this->name);
         $this->firstname = trim($this->firstname);
-        if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->lastname = ucwords(strtolower($this->lastname));
+        if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->lastname = dol_ucwords(dol_strtolower($this->lastname));
 		if (!empty($conf->global->MAIN_ALL_TO_UPPER)) $this->lastname = dol_strtoupper($this->lastname);
-        if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->firstname = ucwords(strtolower($this->firstname));
+        if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->firstname = dol_ucwords(dol_strtolower($this->firstname));
         if (empty($this->socid)) $this->socid = 0;
 		if (empty($this->priv)) $this->priv = 0;
 		if (empty($this->statut)) $this->statut = 0; // This is to convert '' into '0' to avoid bad sql request
@@ -464,9 +464,9 @@ class Contact extends CommonObject
 		$this->entity = ((isset($this->entity) && is_numeric($this->entity)) ? $this->entity : $conf->entity);
 
 		// Clean parameters
-		if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->lastname = ucwords(strtolower($this->lastname));
+		if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->lastname = dol_ucwords(dol_strtolower($this->lastname));
 		if (!empty($conf->global->MAIN_ALL_TO_UPPER)) $this->lastname = dol_strtoupper($this->lastname);
-        if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->firstname = ucwords(strtolower($this->firstname));
+        if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->firstname = dol_ucwords(dol_strtolower($this->firstname));
 
 		$this->lastname = trim($this->lastname) ?trim($this->lastname) : trim($this->lastname);
 		$this->firstname = trim($this->firstname);