diff --git a/Puffer/module.php b/Puffer/module.php
index e4d9016..74f43eb 100644
--- a/Puffer/module.php
+++ b/Puffer/module.php
@@ -11,7 +11,7 @@ class Puffer extends IPSModule
         $this->RegisterPropertyInteger("PufferLeistung", 6000);
         $this->RegisterPropertyInteger("ZeitKonstante", 120);
         $this->RegisterPropertyInteger("Boilerfuehler_PT1", 0);
-        $this->RegisterPropertyBool("Heizkontakt_Puffer", false);
+        $this->RegisterPropertyBoolean("Heizkontakt_Puffer", false);
         $this->RegisterPropertyInteger("Aussentemp", 20);
         $this->RegisterPropertyInteger("MinVT_Temp", 20);
         $this->RegisterPropertyInteger("MaxVT_Temp", 80);