diff --git a/htdocs/main.inc.php b/htdocs/main.inc.php
index e1cb471b58d2f..c24f9fc20360d 100644
--- a/htdocs/main.inc.php
+++ b/htdocs/main.inc.php
@@ -447,9 +447,9 @@ function analyse_sql_and_script(&$var, $type)
                 $dol_authmode=$conf->authmode;	// This properties is defined only when logged, to say what mode was successfully used
                 $dol_tz=$_POST["tz"];
                 $dol_tz_string=$_POST["tz_string"];
-                $dol_tz_string=preg_replace('\s*\(.+\)$','',$dol_tz_string);
-                $dol_tz_string=preg_replace(',','/',$dol_tz_string);
-                $dol_tz_string=preg_replace('\s','_',$dol_tz_string);
+                $dol_tz_string=preg_replace('/\s*\(.+\)$/','',$dol_tz_string);
+                $dol_tz_string=preg_replace('/,/'	,'/',$dol_tz_string);
+                $dol_tz_string=preg_replace('/\s/','_',$dol_tz_string);
                 $dol_dst=0;
                 if (isset($_POST["dst_first"]) && isset($_POST["dst_second"]))
                 {