diff --git a/src/calibre/devices/usbms/device.py b/src/calibre/devices/usbms/device.py
index af2948cf82..2c095d6f7b 100644
--- a/src/calibre/devices/usbms/device.py
+++ b/src/calibre/devices/usbms/device.py
@@ -605,8 +605,9 @@ class Device(DeviceConfig, DevicePlugin):
 
         main, carda, cardb = self.find_device_nodes()
         if main is None:
-            raise DeviceError(_('Unable to detect the %s disk drive. Your '
-            ' kernel is probably exporting a deprecated version of SYSFS.')
+            raise DeviceError(_('Unable to detect the %s disk drive. Either '
+            'the device has already been ejected, or your '
+            'kernel is exporting a deprecated version of SYSFS.')
                     %self.__class__.__name__)
 
         self._linux_mount_map = {}