diff --git a/src/Justimmo/Model/Wrapper/V1/RealtyWrapper.php b/src/Justimmo/Model/Wrapper/V1/RealtyWrapper.php
index 2c4fb58..82aff7c 100644
--- a/src/Justimmo/Model/Wrapper/V1/RealtyWrapper.php
+++ b/src/Justimmo/Model/Wrapper/V1/RealtyWrapper.php
@@ -392,7 +392,7 @@ public function transformSingle($data)
 
         if (isset($xml->flaechen)) {
             $this->map($this->flaechenMapping, $xml->flaechen, $objekt);
-            $objekt->setSurfaceArea($this->cast($xml->flaechen->grundstuecksflaeche));
+            $objekt->setSurfaceArea($this->cast($xml->flaechen->grundstuecksflaeche, 'double'));
 
             foreach ($xml->flaechen->user_defined_simplefield as $simpleField) {
                 $this->mapSimpleField($simpleField, $objekt);