diff --git a/htdocs/adherents/class/adherent.class.php b/htdocs/adherents/class/adherent.class.php
index 3f128ab9c5a..b67ded65c6e 100644
--- a/htdocs/adherents/class/adherent.class.php
+++ b/htdocs/adherents/class/adherent.class.php
@@ -589,8 +589,9 @@ class Adherent extends CommonObject
 		$this->town = ($this->town ? $this->town : $this->town);
 		$this->country_id = ($this->country_id > 0 ? $this->country_id : $this->country_id);
 		$this->state_id = ($this->state_id > 0 ? $this->state_id : $this->state_id);
-		if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->lastname = ucwords(trim($this->lastname));
-		if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->firstname = ucwords(trim($this->firstname));
+		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)) $this->firstname = dol_ucwords(dol_strtolower($this->firstname));
 		$this->note_public = ($this->note_public ? $this->note_public : $this->note_public);
 		$this->note_private = ($this->note_private ? $this->note_private : $this->note_private);
 
diff --git a/htdocs/contact/class/contact.class.php b/htdocs/contact/class/contact.class.php
index ab6e3c732c9..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_ALL_TO_UPPER)) $this->lastname = strtoupper($this->lastname);
-        if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->firstname = ucwords(strtolower($this->firstname));
+        if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->lastname = dol_ucwords(dol_strtolower($this->lastname));
+		if (!empty($conf->global->MAIN_ALL_TO_UPPER)) $this->lastname = dol_strtoupper($this->lastname);
+        if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->firstname = dol_ucwords(dol_strtolower($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_ALL_TO_UPPER)) $this->lastname = strtoupper($this->lastname);
-        if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->firstname = ucwords(strtolower($this->firstname));
+		if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->lastname = dol_ucwords(dol_strtolower($this->lastname));
+		if (!empty($conf->global->MAIN_ALL_TO_UPPER)) $this->lastname = dol_strtoupper($this->lastname);
+        if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->firstname = dol_ucwords(dol_strtolower($this->firstname));
 
 		$this->lastname = trim($this->lastname) ?trim($this->lastname) : trim($this->lastname);
 		$this->firstname = trim($this->firstname);
diff --git a/htdocs/core/lib/functions.lib.php b/htdocs/core/lib/functions.lib.php
index 6b76148d350..df2eab61378 100644
--- a/htdocs/core/lib/functions.lib.php
+++ b/htdocs/core/lib/functions.lib.php
@@ -1086,29 +1086,69 @@ function dol_escape_htmltag($stringtoescape, $keepb = 0, $keepn = 0, $keepmoreta
 	}
 }
 
-
 /**
  * Convert a string to lower. Never use strtolower because it does not works with UTF8 strings.
  *
- * @param 	string		$utf8_string		String to encode
+ * @param 	string		$string		        String to encode
+ * @param   string      $encoding           Character set encoding
  * @return 	string							String converted
  */
-function dol_strtolower($utf8_string)
+function dol_strtolower($string, $encoding = "UTF-8")
 {
-	return mb_strtolower($utf8_string, "UTF-8");
+	if (function_exists('mb_strtolower')) {
+        return mb_strtolower($string, $encoding);
+    } else {
+        return strtolower($string);
+    }
 }
 
 /**
  * Convert a string to upper. Never use strtolower because it does not works with UTF8 strings.
  *
- * @param 	string		$utf8_string		String to encode
+ * @param 	string		$string		        String to encode
+ * @param   string      $encoding           Character set encoding
  * @return 	string							String converted
  */
-function dol_strtoupper($utf8_string)
+function dol_strtoupper($string, $encoding = "UTF-8")
 {
-	return mb_strtoupper($utf8_string, "UTF-8");
+	if (function_exists('mb_strtoupper')) {
+        return mb_strtoupper($string, $encoding);
+    } else {
+        return strtoupper($string);
+    }
 }
 
+/**
+ * Convert first character of the first word of a string to upper. Never use ucfirst because it does not works with UTF8 strings.
+ *
+ * @param   string      $string         String to encode
+ * @param   string      $encoding       Character set encodign
+ * @return  string                      String converted
+ */
+function dol_ucfirst($string, $encoding = "UTF-8")
+{
+    if (function_exists('mb_substr')) {
+        return mb_strtoupper(mb_substr($string, 0, 1, $encoding), $encoding) . mb_substr($string, 1, null, $encoding);
+    } else {
+        return ucfirst($string);
+    }
+}
+
+/**
+ * Convert first character of all the words of a string to upper. Never use ucfirst because it does not works with UTF8 strings.
+ *
+ * @param   string      $string         String to encode
+ * @param   string      $encoding       Character set encodign
+ * @return  string                      String converted
+ */
+function dol_ucwords($string, $encoding = "UTF-8")
+{
+    if (function_exists('mb_convert_case')) {
+        return mb_convert_case($string, MB_CASE_TITLE, $encoding);
+    } else {
+        return ucwords($string);
+    }
+}
 
 /**
  *	Write log message into outputs. Possible outputs can be:
diff --git a/htdocs/societe/class/societe.class.php b/htdocs/societe/class/societe.class.php
index 9078b2146d4..3047e986df8 100644
--- a/htdocs/societe/class/societe.class.php
+++ b/htdocs/societe/class/societe.class.php
@@ -789,8 +789,8 @@ class Societe extends CommonObject
 		// Clean parameters
 		if (empty($this->status)) $this->status = 0;
 		$this->name = $this->name ?trim($this->name) : trim($this->nom);
-		if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->name = ucwords($this->name);
-		if (!empty($conf->global->MAIN_ALL_TO_UPPER)) $this->name = strtoupper($this->name);
+		if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->name = dol_ucwords(dol_strtolower($this->name));
+		if (!empty($conf->global->MAIN_ALL_TO_UPPER)) $this->name = dol_strtoupper($this->name);
 		$this->nom = $this->name; // For backward compatibility
 		if (empty($this->client))      $this->client = 0;
 		if (empty($this->fournisseur)) $this->fournisseur = 0;
@@ -1094,8 +1094,8 @@ class Societe extends CommonObject
 
 		$now = dol_now();
 
-		if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->name = ucwords($this->name);
-		if (!empty($conf->global->MAIN_ALL_TO_UPPER)) $this->name = strtoupper($this->name);
+		if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->name = dol_ucwords(dol_strtolower($this->name));
+		if (!empty($conf->global->MAIN_ALL_TO_UPPER)) $this->name = dol_strtoupper($this->name);
 		// Clean parameters
 		$this->id = $id;
 		$this->entity = ((isset($this->entity) && is_numeric($this->entity)) ? $this->entity : $conf->entity);
diff --git a/htdocs/user/class/user.class.php b/htdocs/user/class/user.class.php
index b6db00d2d16..87f36cab15a 100644
--- a/htdocs/user/class/user.class.php
+++ b/htdocs/user/class/user.class.php
@@ -1123,9 +1123,9 @@ class User extends CommonObject
 
 		// Clean parameters
 
-		if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->lastname = ucwords($this->lastname);
-		if (!empty($conf->global->MAIN_ALL_TO_UPPER)) $this->lastname = strtoupper($this->lastname);
-		if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->firstname = ucwords($this->firstname);
+		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)) $this->firstname = dol_ucwords(dol_strtolower($this->firstname));
 
 		$this->login = trim($this->login);
 		if (!isset($this->entity)) $this->entity = $conf->entity; // If not defined, we use default value
@@ -1468,9 +1468,9 @@ class User extends CommonObject
 
 		// Clean parameters
 
-		if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->lastname = ucwords($this->lastname);
-		if (!empty($conf->global->MAIN_ALL_TO_UPPER)) $this->lastname = strtoupper($this->lastname);
-		if (!empty($conf->global->MAIN_FIRST_TO_UPPER)) $this->firstname = ucwords($this->firstname);
+		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)) $this->firstname = dol_ucwords(dol_strtolower($this->firstname));
 
 		$this->lastname     = trim($this->lastname);
 		$this->firstname    = trim($this->firstname);