diff --git a/src/nm-device-interface.c b/src/nm-device-interface.c
index 84646831e..5647adb42 100644
--- a/src/nm-device-interface.c
+++ b/src/nm-device-interface.c
@@ -137,7 +137,7 @@ nm_device_interface_init (gpointer g_iface)
 							"DeviceType",
 							"DeviceType",
 							0, G_MAXUINT32, NM_DEVICE_TYPE_UNKNOWN,
-							G_PARAM_READABLE));
+							G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
 
 	g_object_interface_install_property
 		(g_iface, g_param_spec_boolean (NM_DEVICE_INTERFACE_MANAGED,
diff --git a/src/nm-device.c b/src/nm-device.c
index b34795ecd..7cefbe508 100644
--- a/src/nm-device.c
+++ b/src/nm-device.c
@@ -2248,6 +2248,10 @@ set_property (GObject *object, guint prop_id,
 	case NM_DEVICE_INTERFACE_PROP_MANAGED:
 		priv->managed = g_value_get_boolean (value);
 		break;
+	case NM_DEVICE_INTERFACE_PROP_DEVICE_TYPE:
+		g_return_if_fail (priv->type == NM_DEVICE_TYPE_UNKNOWN);
+		priv->type = g_value_get_uint (value);
+		break;
 	case NM_DEVICE_INTERFACE_PROP_TYPE_DESC:
 		g_free (priv->type_desc);
 		priv->type_desc = g_value_dup_string (value);