diff --git a/htdocs/comm/list.php b/htdocs/comm/list.php
index e03b7473c55..2c256ec2fda 100644
--- a/htdocs/comm/list.php
+++ b/htdocs/comm/list.php
@@ -117,11 +117,11 @@ if ($catid == -2)        $sql.= " AND cs.fk_categorie IS NULL";
 if ($search_categ > 0)   $sql.= " AND cs.fk_categorie = ".$search_categ;
 if ($search_categ == -2) $sql.= " AND cs.fk_categorie IS NULL";
 if ($search_nom) {
-	$sql .= natural_search(array('s.nom'), $search_nom);
+	$sql .= natural_search('s.nom', $search_nom);
 }
 if ($search_zipcode) $sql.= " AND s.zip LIKE '".$db->escape($search_zipcode)."%'";
 if ($search_town) {
-	$sql .= natural_search(array('s.town'), $search_town);
+	$sql .= natural_search('s.town', $search_town);
 }
 if ($search_code)  $sql.= " AND s.code_client LIKE '%".$db->escape($search_code)."%'";
 if ($search_compta) $sql.= " AND s.code_compta LIKE '%".$db->escape($search_compta)."%'";
diff --git a/htdocs/comm/propal/list.php b/htdocs/comm/propal/list.php
index d0a7228e21e..ae489ce83c0 100644
--- a/htdocs/comm/propal/list.php
+++ b/htdocs/comm/propal/list.php
@@ -162,16 +162,16 @@ if (! $user->rights->societe->client->voir && ! $socid) //restriction
 	$sql.= " AND s.rowid = sc.fk_soc AND sc.fk_user = " .$user->id;
 }
 if ($search_town) {//restriction
-	$sql .= natural_search(array('s.town'), $search_town);
+	$sql .= natural_search('s.town', $search_town);
 }
 if ($search_ref) {
-	$sql .= natural_search(array('p.ref'), $search_ref);
+	$sql .= natural_search('p.ref', $search_ref);
 }
 if ($search_refcustomer) {
-	$sql .= natural_search(array('p.ref_client'), $search_refcustomer);
+	$sql .= natural_search('p.ref_client', $search_refcustomer);
 }
 if ($search_societe) {
-	$sql .= natural_search(array('s.nom'), $search_societe);
+	$sql .= natural_search('s.nom', $search_societe);
 }
 if ($search_author)
 {
diff --git a/htdocs/comm/prospect/list.php b/htdocs/comm/prospect/list.php
index eabd74fa64b..959c271b85e 100644
--- a/htdocs/comm/prospect/list.php
+++ b/htdocs/comm/prospect/list.php
@@ -195,14 +195,14 @@ if ($catid == -2)        $sql.= " AND cs.fk_categorie IS NULL";
 if ($search_categ > 0)   $sql.= " AND cs.fk_categorie = ".$search_categ;
 if ($search_categ == -2) $sql.= " AND cs.fk_categorie IS NULL";
 if ($search_nom) {
-	$sql .= natural_search(array('s.nom'), $search_nom);
+	$sql .= natural_search('s.nom', $search_nom);
 }
 if ($search_zipcode) $sql .= " AND s.zip LIKE '".$db->escape(strtolower($search_zipcode))."%'";
 if ($search_town) {
-	$sql .= natural_search(array('s.town'), $search_town);
+	$sql .= natural_search('s.town', $search_town);
 }
 if ($search_state) {
-	$sql .= natural_search(array('d.nom'), $search_state);
+	$sql .= natural_search('d.nom', $search_state);
 }
 if ($search_datec) $sql .= " AND s.datec LIKE '%".$db->escape($search_datec)."%'";
 // Insert levels filters
@@ -216,7 +216,7 @@ if ($search_sale)
 	$sql .= " AND sc.fk_user = ".$db->escape($search_sale);
 }
 if ($socname) {
-	$sql .= natural_search(array('s.nom'), $search_nom);
+	$sql .= natural_search('s.nom', $search_nom);
 	$sortfield = "s.nom";
 	$sortorder = "ASC";
 }
diff --git a/htdocs/commande/liste.php b/htdocs/commande/liste.php
index 13bbac17e50..9bf7caf379a 100644
--- a/htdocs/commande/liste.php
+++ b/htdocs/commande/liste.php
@@ -127,7 +127,7 @@ $sql.= ' AND c.entity = '.$conf->entity;
 if ($socid)	$sql.= ' AND s.rowid = '.$socid;
 if (!$user->rights->societe->client->voir && !$socid) $sql.= " AND s.rowid = sc.fk_soc AND sc.fk_user = " .$user->id;
 if ($sref) {
-	$sql .= natural_search(array('c.ref'), $sref);
+	$sql .= natural_search('c.ref', $sref);
 }
 if ($sall)
 {
@@ -187,7 +187,7 @@ else if ($deliveryyear > 0)
 }
 if (!empty($snom))
 {
-	$sql .= natural_search(array('s.nom'), $snom);
+	$sql .= natural_search('s.nom', $snom);
 }
 if (!empty($sref_client))
 {
diff --git a/htdocs/compta/dons/liste.php b/htdocs/compta/dons/liste.php
index 73fc2b0ba48..56c66d4fdce 100644
--- a/htdocs/compta/dons/liste.php
+++ b/htdocs/compta/dons/liste.php
@@ -76,7 +76,7 @@ if (trim($search_ref) != '')
 }
 if (trim($search_company) != '')
 {
-    $sql .= natural_search(array('d.societe'), $search_company);
+    $sql .= natural_search('d.societe', $search_company);
 }
 if (trim($search_name) != '')
 {
diff --git a/htdocs/compta/facture/list.php b/htdocs/compta/facture/list.php
index f1835fd41f1..7a5749006a6 100644
--- a/htdocs/compta/facture/list.php
+++ b/htdocs/compta/facture/list.php
@@ -175,11 +175,11 @@ if ($filtre)
 }
 if ($search_ref)
 {
-    $sql .= natural_search(array('f.facnumber'), $search_ref);
+    $sql .= natural_search('f.facnumber', $search_ref);
 }
 if ($search_societe)
 {
-    $sql .= natural_search(array('s.nom'), $search_societe);
+    $sql .= natural_search('s.nom', $search_societe);
 }
 if ($search_montant_ht)
 {
diff --git a/htdocs/compta/paiement/liste.php b/htdocs/compta/paiement/liste.php
index a4952b66f41..5e1653b3ec3 100644
--- a/htdocs/compta/paiement/liste.php
+++ b/htdocs/compta/paiement/liste.php
@@ -113,7 +113,7 @@ else
     if (GETPOST("search_account") > 0)      $sql .=" AND b.fk_account=".GETPOST("search_account",'int');
     if (GETPOST("search_paymenttype") != "")  $sql .=" AND c.code='".GETPOST("search_paymenttype")."'";
     if (GETPOST("search_amount"))      		$sql .=" AND p.amount=".price2num(GETPOST("search_amount"));
-    if (GETPOST("search_company"))     		$sql .= natural_search(array('s.nom'), GETPOST('search_company'));
+    if (GETPOST("search_company"))     		$sql .= natural_search('s.nom', GETPOST('search_company'));
 }
 $sql.= $db->order($sortfield,$sortorder);
 $sql.= $db->plimit($limit+1, $offset);
diff --git a/htdocs/contact/list.php b/htdocs/contact/list.php
index 11ddd4ae72f..686e8766b44 100644
--- a/htdocs/contact/list.php
+++ b/htdocs/contact/list.php
@@ -150,16 +150,16 @@ if ($search_categ > 0)   $sql.= " AND cs.fk_categorie = ".$search_categ;
 if ($search_categ == -2) $sql.= " AND cs.fk_categorie IS NULL";
 
 if ($search_lastname) {      // filter on lastname
-    $sql .= natural_search(array('p.lastname'), $search_lastname);
+    $sql .= natural_search('p.lastname', $search_lastname);
 }
 if ($search_firstname) {   // filter on firstname
-    $sql .= natural_search(array('p.firstname'), $search_firstname);
+    $sql .= natural_search('p.firstname', $search_firstname);
 }
 if ($search_societe) {  // filtre sur la societe
-    $sql .= natural_search(array('s.nom'), $search_societe);
+    $sql .= natural_search('s.nom', $search_societe);
 }
 if (strlen($search_poste)) {  // filtre sur la societe
-    $sql .= natural_search(array('p.poste'), $search_poste);
+    $sql .= natural_search('p.poste', $search_poste);
 }
 if (strlen($search_phone))
 {
diff --git a/htdocs/contrat/liste.php b/htdocs/contrat/liste.php
index 2a90ce37d1d..40a6811e41b 100644
--- a/htdocs/contrat/liste.php
+++ b/htdocs/contrat/liste.php
@@ -81,7 +81,7 @@ $sql.= " AND c.entity = ".$conf->entity;
 if ($socid) $sql.= " AND s.rowid = ".$socid;
 if (!$user->rights->societe->client->voir && !$socid) $sql.= " AND s.rowid = sc.fk_soc AND sc.fk_user = " .$user->id;
 if ($search_nom) {
-    $sql .= natural_search(array('s.nom'), $search_nom);
+    $sql .= natural_search('s.nom', $search_nom);
 }
 if ($search_contract) {
     $sql .= natural_search(array('c.rowid', 'c.ref'), $search_contract);
diff --git a/htdocs/core/lib/functions.lib.php b/htdocs/core/lib/functions.lib.php
index 2604073fb63..ca2a68c3454 100644
--- a/htdocs/core/lib/functions.lib.php
+++ b/htdocs/core/lib/functions.lib.php
@@ -4439,7 +4439,7 @@ if (! function_exists('getmypid'))
 
 /**
  * Natural search
- * @param array[string] $fields array filled with the fields names in the SQL query
+ * @param mixed $fields string or array of strings filled with the fields names in the SQL query
  * @param string $value the value to look for
  * @return string $res the statement to append to the SQL query
  * */
@@ -4448,6 +4448,9 @@ function natural_search($fields, $value)
     global $db;
     $crits = explode(' ', $value);
     $res = "";
+    if (! is_array($fields)) {
+        $fields = array($fields);
+    }
     $end = count($fields);
     $end2 = count($crits);
     $j = 0;
diff --git a/htdocs/fichinter/list.php b/htdocs/fichinter/list.php
index eed071cb42f..93142ed2dc3 100644
--- a/htdocs/fichinter/list.php
+++ b/htdocs/fichinter/list.php
@@ -75,10 +75,10 @@ $sql.= " LEFT JOIN ".MAIN_DB_PREFIX."fichinterdet as fd ON fd.fk_fichinter = f.r
 $sql.= " WHERE f.fk_soc = s.rowid ";
 $sql.= " AND f.entity = ".$conf->entity;
 if ($search_ref) {
-    $sql .= natural_search(array('f.ref'), $search_ref);
+    $sql .= natural_search('f.ref', $search_ref);
 }
 if ($search_company) {
-    $sql .= natural_search(array('s.nom'), $search_company);
+    $sql .= natural_search('s.nom', $search_company);
 }
 if ($search_desc) {
     $sql .= natural_search(array('f.description', 'fd.description'), $search_desc);
diff --git a/htdocs/fourn/commande/liste.php b/htdocs/fourn/commande/liste.php
index bf4f274dc43..e56c60a68dd 100644
--- a/htdocs/fourn/commande/liste.php
+++ b/htdocs/fourn/commande/liste.php
@@ -93,11 +93,11 @@ $sql.= " AND cf.entity = ".$conf->entity;
 if (!$user->rights->societe->client->voir && !$socid) $sql.= " AND s.rowid = sc.fk_soc AND sc.fk_user = " .$user->id;
 if ($sref)
 {
-	$sql .= natural_search(array('cf.ref'), $sref);
+	$sql .= natural_search('cf.ref', $sref);
 }
 if ($snom)
 {
-	$sql .= natural_search(array('s.nom'), $snom);
+	$sql .= natural_search('s.nom', $snom);
 }
 if ($suser)
 {
diff --git a/htdocs/fourn/facture/list.php b/htdocs/fourn/facture/list.php
index 6f93fd3c61e..bc7632350c1 100644
--- a/htdocs/fourn/facture/list.php
+++ b/htdocs/fourn/facture/list.php
@@ -132,11 +132,11 @@ if (GETPOST('filtre'))
 if (GETPOST("search_ref"))
 {
 	if (is_numeric(GETPOST("search_ref"))) $sql .= natural_search(array('fac.rowid', 'fac.ref'), GETPOST('search_ref'));// For backward compatibility
-	else $sql .= natural_search(array('fac.ref'), GETPOST("search_ref"));
+	else $sql .= natural_search('fac.ref', GETPOST("search_ref"));
 }
 if (GETPOST("search_ref_supplier"))
 {
-	$sql .= natural_search(array('fac.ref_supplier'), GETPOST('search_ref_supplier'));
+	$sql .= natural_search('fac.ref_supplier', GETPOST('search_ref_supplier'));
 }
 if ($month > 0)
 {
@@ -151,12 +151,12 @@ else if ($year > 0)
 }
 if (GETPOST("search_libelle"))
 {
-    $sql .= natural_search(array('fac.libelle'), GETPOST('search_libelle'));
+    $sql .= natural_search('fac.libelle', GETPOST('search_libelle'));
 }
 
 if (GETPOST("search_societe"))
 {
-    $sql .= natural_search(array('s.nom'), GETPOST('search_societe'));
+    $sql .= natural_search('s.nom', GETPOST('search_societe'));
 }
 
 if (GETPOST("search_montant_ht"))
diff --git a/htdocs/fourn/liste.php b/htdocs/fourn/liste.php
index c4256625a3a..78668103606 100644
--- a/htdocs/fourn/liste.php
+++ b/htdocs/fourn/liste.php
@@ -90,16 +90,16 @@ $sql.= " AND s.entity IN (".getEntity('societe', 1).")";
 if (!$user->rights->societe->client->voir && !$socid) $sql .= " AND s.rowid = sc.fk_soc AND sc.fk_user = " .$user->id;
 if ($socid) $sql .= " AND s.rowid = ".$socid;
 if ($socname) {
-	$sql .= natural_search(array('s.nom'), $socname);
+	$sql .= natural_search('s.nom', $socname);
 	$sortfield = "s.nom";
 	$sortorder = "ASC";
 }
 if ($search_nom) {
-	$sql .= natural_search(array('s.nom'), $search_nom);
+	$sql .= natural_search('s.nom', $search_nom);
 }
 if ($search_zipcode) $sql .= " AND s.zip LIKE '".$db->escape($search_zipcode)."%'";
 if ($search_town) {
-	$sql .= natural_search(array('s.town'), $search_town);
+	$sql .= natural_search('s.town', $search_town);
 }
 if ($search_code_fournisseur)   $sql .= " AND s.code_fournisseur LIKE '%".$db->escape($search_code_fournisseur)."%'";
 if ($search_compta_fournisseur) $sql .= " AND s.code_compta_fournisseur LIKE '%".$db->escape($search_compta_fournisseur)."%'";
diff --git a/htdocs/fourn/product/liste.php b/htdocs/fourn/product/liste.php
index bc82a48c907..33439ed05fd 100644
--- a/htdocs/fourn/product/liste.php
+++ b/htdocs/fourn/product/liste.php
@@ -106,11 +106,11 @@ else
 	}
 	if ($sref)
 	{
-		$sql .= natural_search(array('p.ref'), $sref);
+		$sql .= natural_search('p.ref', $sref);
 	}
 	if ($snom)
 	{
-		$sql .= natural_search(array('p.label'), $snom);
+		$sql .= natural_search('p.label', $snom);
 	}
 	if($catid)
 	{
@@ -119,7 +119,7 @@ else
 }
 if ($sRefSupplier)
 {
-	$sql .= natural_search(array('ppf.ref_fourn'), $sRefSupplier);
+	$sql .= natural_search('ppf.ref_fourn', $sRefSupplier);
 }
 if ($fourn_id > 0)
 {
diff --git a/htdocs/product/liste.php b/htdocs/product/liste.php
index 2ad7147ac63..af1dfea171b 100644
--- a/htdocs/product/liste.php
+++ b/htdocs/product/liste.php
@@ -162,7 +162,7 @@ else
     	else $sql.= " AND p.fk_product_type <> '1'";
     }
 	if ($sref) {
-		$sql .= natural_search(array('p.ref'), $sref);
+		$sql .= natural_search('p.ref', $sref);
 	}
     if ($sbarcode) $sql.= " AND p.barcode LIKE '%".$sbarcode."%'";
     if ($snom)
diff --git a/htdocs/projet/liste.php b/htdocs/projet/liste.php
index bb07738e09f..23ad699b512 100644
--- a/htdocs/projet/liste.php
+++ b/htdocs/projet/liste.php
@@ -87,15 +87,15 @@ if ($mine || ! $user->rights->projet->all->lire) $sql.= " AND p.rowid IN (".$pro
 if ($socid) $sql.= "  AND (p.fk_soc IS NULL OR p.fk_soc = 0 OR p.fk_soc = ".$socid.")";
 if ($search_ref)
 {
-	$sql .= natural_search(array('p.ref'), $search_ref);
+	$sql .= natural_search('p.ref', $search_ref);
 }
 if ($search_label)
 {
-	$sql .= natural_search(array('p.title'), $search_label);
+	$sql .= natural_search('p.title', $search_label);
 }
 if ($search_societe)
 {
-	$sql .= natural_search(array('s.nom'), $search_societe);
+	$sql .= natural_search('s.nom', $search_societe);
 }
 $sql.= $db->order($sortfield,$sortorder);
 $sql.= $db->plimit($conf->liste_limit+1, $offset);