diff --git a/wp-includes/wp-db.php b/wp-includes/wp-db.php
index 9df8329601..2600d8e22a 100644
--- a/wp-includes/wp-db.php
+++ b/wp-includes/wp-db.php
@@ -1135,10 +1135,13 @@ class wpdb {
 
 		$this->is_mysql = true;
 
+		$new_link = defined( 'MYSQL_NEW_LINK' ) ? MYSQL_NEW_LINK : true;
+		$client_flags = defined( 'MYSQL_CLIENT_FLAGS' ) ? MYSQL_CLIENT_FLAGS : 0;
+
 		if ( WP_DEBUG ) {
-			$this->dbh = mysql_connect( $this->dbhost, $this->dbuser, $this->dbpassword, true );
+			$this->dbh = mysql_connect( $this->dbhost, $this->dbuser, $this->dbpassword, $new_link, $client_flags );
 		} else {
-			$this->dbh = @mysql_connect( $this->dbhost, $this->dbuser, $this->dbpassword, true );
+			$this->dbh = @mysql_connect( $this->dbhost, $this->dbuser, $this->dbpassword, $new_link, $client_flags );
 		}
 
 		if ( !$this->dbh ) {