diff --git a/bin/smartdata/Backend.php b/bin/smartdata/Backend.php
index 36ad75a9dde21dd43ba54e126fe588f69a4433b8..adab199e8e44e641924ab9e294391da71f19921d 100644
--- a/bin/smartdata/Backend.php
+++ b/bin/smartdata/Backend.php
@@ -3219,7 +3219,7 @@ class Backend_V1_1 extends Backend_Common
                                 $smartdata = new StaticSmartData($series->unit,$value,$error,$conf,$x,$y,$z,$time,$d,$gw);
                                 break;
                             case SmartData::MOBILE_VERSION:
-                                $smartdata = new MobileSmartData($series->unit,$value,$error,$conf,$x,$y,$z,$time,$d,$gw, null);
+                                $smartdata = new MobileSmartData($series->unit, $value, $error, $conf, $x, $y, $z, $time, $d, $gw, $series->signature );
                                 break;
                             default:
                                 continue 2;