diff --git a/htdocs/lib/functions.lib.php b/htdocs/lib/functions.lib.php
index aff508e2a06..d0f120898fa 100644
--- a/htdocs/lib/functions.lib.php
+++ b/htdocs/lib/functions.lib.php
@@ -4371,7 +4371,7 @@ function complete_head_from_modules($conf,$langs,$object,&$head,&$h,$type,$mode=
         foreach ($conf->tabs_modules[$type] as $value)
         {
             $values=explode(':',$value);
-            if ($mode == 'add')
+            if ($mode == 'add' && ! preg_match('/^\-/',$values[1]))
             {
                 if (sizeof($values) == 6)       // new declaration with permissions
                 {
@@ -4404,7 +4404,7 @@ function complete_head_from_modules($conf,$langs,$object,&$head,&$h,$type,$mode=
                     $h++;
                 }
             }
-            else if ($mode == 'remove')
+            else if ($mode == 'remove' && preg_match('/^\-/',$values[1]))
             {
                 if ($values[0] != $type) continue;
                 $tabname=str_replace('-','',$values[1]);