diff --git a/htdocs/admin/system/dolibarr.php b/htdocs/admin/system/dolibarr.php
index 2a343808c8b..c357d0148d4 100644
--- a/htdocs/admin/system/dolibarr.php
+++ b/htdocs/admin/system/dolibarr.php
@@ -87,7 +87,7 @@ $var=!$var;
 print '<tr '.$bc[$var].'><td width="300">'.$langs->trans("CurrentTheme").'</td><td colspan="2">'.$conf->theme.'</td></tr>'."\n";
 $var=!$var;
 print '<tr '.$bc[$var].'><td width="300">'.$langs->trans("CurrentMenuHandler").'</td><td colspan="2">';
-if (preg_match('/^smartphone/',$conf->smart_menu) && isset($conf->browser->phone)) print $conf->smart_menu;
+if (preg_match('/^smartphone/',$conf->smart_menu) && ! empty($conf->browser->phone)) print $conf->smart_menu;
 else print $conf->top_menu;
 print '</td></tr>'."\n";
 print '</table>';
diff --git a/htdocs/core/lib/security2.lib.php b/htdocs/core/lib/security2.lib.php
index 10846f14e16..eb9156fd4b8 100644
--- a/htdocs/core/lib/security2.lib.php
+++ b/htdocs/core/lib/security2.lib.php
@@ -185,7 +185,7 @@ function dol_loginfunction($langs,$conf,$mysoc)
 	if (! empty($conf->global->MAIN_APPLICATION_TITLE)) $title=$conf->global->MAIN_APPLICATION_TITLE;
 
 	// Select templates
-	if (preg_match('/^smartphone/',$conf->smart_menu) && isset($conf->browser->phone))
+	if (preg_match('/^smartphone/',$conf->smart_menu) && ! empty($conf->browser->phone))
 	{
 		$template_dir = DOL_DOCUMENT_ROOT.'/theme/phones/smartphone/tpl/';
 	}
diff --git a/htdocs/index.php b/htdocs/index.php
index e5d64da0357..1dc2a2b06f4 100644
--- a/htdocs/index.php
+++ b/htdocs/index.php
@@ -56,7 +56,7 @@ if (!isset($conf->global->MAIN_INFO_SOCIETE_NOM) || empty($conf->global->MAIN_IN
  */
 
 // If smartphone mode, we do not show main page, we show only menu
-if (preg_match('/^smartphone/',$conf->smart_menu) && isset($conf->browser->phone))
+if (preg_match('/^smartphone/',$conf->smart_menu) && ! empty($conf->browser->phone))
 {
     $limitmenuto=GETPOST('limitmenuto')?GETPOST('limitmenuto'):0;
     $limitmenuto=1;	// A virer
diff --git a/htdocs/main.inc.php b/htdocs/main.inc.php
index 5409712b6b0..1dc14515aba 100644
--- a/htdocs/main.inc.php
+++ b/htdocs/main.inc.php
@@ -1503,7 +1503,7 @@ function main_area($title='')
     print "\n";
 
     print '<div class="fiche"> <!-- begin div class="fiche" -->'."\n";
-    if (preg_match('/^smartphone/',$conf->smart_menu) && isset($conf->browser->phone))
+    if (preg_match('/^smartphone/',$conf->smart_menu) && ! empty($conf->browser->phone))
     {
         print '<div data-role="page"> <!-- begin div data-role="page" -->';
 
@@ -1628,7 +1628,7 @@ if (! function_exists("llxFooter"))
         }
 
         print "\n\n";
-        if (preg_match('/^smartphone/',$conf->smart_menu) && isset($conf->browser->phone))
+        if (preg_match('/^smartphone/',$conf->smart_menu) && ! empty($conf->browser->phone))
         {
             print '</div> <!-- end div data-role="content" -->'."\n";
             print '</div> <!-- end div data-role="page" -->'."\n";
diff --git a/htdocs/user/passwordforgotten.php b/htdocs/user/passwordforgotten.php
index 86b263807bd..2becad4f564 100644
--- a/htdocs/user/passwordforgotten.php
+++ b/htdocs/user/passwordforgotten.php
@@ -150,7 +150,7 @@ $title='Dolibarr '.DOL_VERSION;
 if (! empty($conf->global->MAIN_APPLICATION_TITLE)) $title=$conf->global->MAIN_APPLICATION_TITLE;
 
 // Select templates
-if (preg_match('/^smartphone/',$conf->smart_menu) && isset($conf->browser->phone))
+if (preg_match('/^smartphone/',$conf->smart_menu) && ! empty($conf->browser->phone))
 {
     $template_dir = DOL_DOCUMENT_ROOT.'/theme/phones/smartphone/tpl/';
 }