diff --git a/tuned/plugins/plugin_disk.py b/tuned/plugins/plugin_disk.py

index e799895..6101621 100644

--- a/tuned/plugins/plugin_disk.py

+++ b/tuned/plugins/plugin_disk.py

@@ -31,10 +31,10 @@ class DiskPlugin(hotplug.Plugin):

 		self._free_devices = self._devices.copy()

 	def _device_is_supported(cls, device):

-		return  device.device_type == "disk" \

-			and device.attributes.get("removable", None) == "0" \

-			and device.parent is not None \

-			and device.parent.subsystem in ["scsi", "virtio"]

+		return  device.device_type == "disk" and \

+			device.attributes.get("removable", None) == "0" and \

+			(device.parent is None or \

+					device.parent.subsystem in ["scsi", "virtio"])

 	def _hardware_events_init(self):

 		self._hardware_inventory.subscribe(self, "block", self._hardware_events_callback)