diff --git a/htdocs/core/db/mssql.class.php b/htdocs/core/db/mssql.class.php
index f1396ab1d53..a9a3ac1afd4 100644
--- a/htdocs/core/db/mssql.class.php
+++ b/htdocs/core/db/mssql.class.php
@@ -43,8 +43,8 @@ class DoliDBMssql
 	static $forcecollate='latin1_swedish_ci';
 	//! Version min database
 	static $versionmin=array(2000);
-	//! Resultset de la derniere requete
-	var $results;
+	//! Resultset of last request
+	private $results;
 	//! 1 si connecte, 0 sinon
 	var $connected;
 	//! 1 si base selectionne, 0 sinon
diff --git a/htdocs/core/db/mysql.class.php b/htdocs/core/db/mysql.class.php
index de6e1b515b4..c51b995d382 100644
--- a/htdocs/core/db/mysql.class.php
+++ b/htdocs/core/db/mysql.class.php
@@ -44,7 +44,7 @@ class DoliDBMysql
 	//! Version min database
 	static $versionmin=array(3,1,0);
 	//! Resultset of last request
-	var $results;
+	private $results;
 	//! 1 if connected, 0 else
 	var $connected;
 	//! 1 if database selected, 0 else
diff --git a/htdocs/core/db/mysqli.class.php b/htdocs/core/db/mysqli.class.php
index 53f8c005feb..8f9a1aea674 100644
--- a/htdocs/core/db/mysqli.class.php
+++ b/htdocs/core/db/mysqli.class.php
@@ -43,8 +43,8 @@ class DoliDBMysqli
     static $forcecollate='utf8_general_ci';	// latin1_swedish_ci, utf8_general_ci
     //! Version min database
     static $versionmin=array(4,1,0);
-    //! Resultset of last request
-    var $results;
+	//! Resultset of last request
+	private $results;
     //! 1 if connected, 0 else
     var $connected;
     //! 1 if database selected, 0 else
diff --git a/htdocs/core/db/pgsql.class.php b/htdocs/core/db/pgsql.class.php
index c04016a9ec4..a28d6762a30 100644
--- a/htdocs/core/db/pgsql.class.php
+++ b/htdocs/core/db/pgsql.class.php
@@ -44,7 +44,8 @@ class DoliDBPgsql
 	//! Version min database
 	static $versionmin=array(8,4,0);	// Version min database
 
-	var $results;                 // Resultset de la derniere requete
+	//! Resultset of last request
+	private $results;
 
 	var $connected;               // 1 si connecte, 0 sinon
 	var $database_selected;       // 1 si base selectionne, 0 sinon
diff --git a/htdocs/core/db/sqlite.class.php b/htdocs/core/db/sqlite.class.php
index a5eb35bac88..9155baa830b 100644
--- a/htdocs/core/db/sqlite.class.php
+++ b/htdocs/core/db/sqlite.class.php
@@ -43,8 +43,8 @@ class DoliDBSqlite
     static $forcecollate='utf8_general_ci';	// latin1_swedish_ci, utf8_general_ci
     //! Version min database
     static $versionmin=array(3,0,0);
-    //! Resultset of last request
-    var $results;
+	//! Resultset of last request
+	private $results;
     //! 1 if connected, 0 else
     var $connected;
     //! 1 if database selected, 0 else