diff --git a/src/cryptobox/web/sites.py b/src/cryptobox/web/sites.py
index a637893..79ecc37 100644
--- a/src/cryptobox/web/sites.py
+++ b/src/cryptobox/web/sites.py
@@ -324,7 +324,7 @@ class WebInterfaceSites:
             ## it will get ignored for non-volume plugins
             plugin.device = None
             if device and self.__set_device(device):
-                plugin.device = self.cbox.get_container(device)
+                plugin.device = self.cbox.get_container(device).device
             ## check the device argument of volume plugins
             if "volume" in plugin.plugin_capabilities:
                 ## initialize the dataset of the selected device if necessary