diff --git a/htdocs/lib/functions.lib.php b/htdocs/lib/functions.lib.php
index 456855be08a..62d8fda0181 100644
--- a/htdocs/lib/functions.lib.php
+++ b/htdocs/lib/functions.lib.php
@@ -1676,7 +1676,7 @@ function dol_move_uploaded_file($src_file, $dest_file, $allowoverwrite)
 	$return=move_uploaded_file($src_file, $file_name);
 	if ($return)
 	{	
-		@chmod($file_name, $conf->global->MAIN_UMASK);
+		if (! empty($conf->global->MAIN_UMASK)) @chmod($file_name, $conf->global->MAIN_UMASK);
 		dolibarr_syslog("Functions.lib::dol_move_uploaded_file Success to move ".$src_file." to ".$file_name." - Umask=".$conf->global->MAIN_UMASK, LOG_DEBUG);
 		return 1;
 	}
diff --git a/htdocs/lib/ldap.class.php b/htdocs/lib/ldap.class.php
index 49a46fc6cf1..c14b966ef5a 100644
--- a/htdocs/lib/ldap.class.php
+++ b/htdocs/lib/ldap.class.php
@@ -600,7 +600,7 @@ class Ldap
 			// We change mod to allow file to be overwritten if dump is launched
 			// from command line or a web session.
 			// 0666 = rw-rw-rw-
-			@chmod($file, $conf->global->MAIN_UMASK);
+			if (! empty($conf->global->MAIN_UMASK)) @chmod($file, $conf->global->MAIN_UMASK);
 			return 1;
 		}
 		else
diff --git a/htdocs/lib/xcal.lib.php b/htdocs/lib/xcal.lib.php
index 56f4cf6fb75..2ace3e542ce 100644
--- a/htdocs/lib/xcal.lib.php
+++ b/htdocs/lib/xcal.lib.php
@@ -316,7 +316,7 @@ function build_rssfile($format='rss',$title,$desc,$events_array,$outputfile,$fil
 		// We change mod to allow file to be overwritten if dump is launched
 		// from command line or a web session.
 		// 0666 = rw-rw-rw-
-		@chmod($fichier, $conf->global->MAIN_UMASK);
+		if (! empty($conf->global->MAIN_UMASK)) @chmod($fichier, $conf->global->MAIN_UMASK);
 	}
 }