diff --git a/src/calibre/devices/cybookg3/driver.py b/src/calibre/devices/cybookg3/driver.py
index c3a4fa94b0..5458fbbffb 100644
--- a/src/calibre/devices/cybookg3/driver.py
+++ b/src/calibre/devices/cybookg3/driver.py
@@ -7,7 +7,6 @@ Device driver for Bookeen's Cybook Gen 3
 import os, shutil
 from itertools import cycle
 
-from calibre.ebooks.metadata import authors_to_string
 from calibre.devices.errors import DeviceError, FreeSpaceError
 from calibre.devices.usbms.driver import USBMS
 import calibre.devices.cybookg3.t2b as t2b
@@ -92,8 +91,8 @@ class CYBOOKG3(USBMS):
                             break
 
                 if newpath == path:
-                    newpath = os.path.join(newpath, authors_to_string(mdata.get('authors', '')))
-                    newpath = os.path.join(newpath, mdata.get('title', ''))
+                    newpath = os.path.join(newpath, mdata.get('authors', _('Unknown')))
+                    newpath = os.path.join(newpath, mdata.get('title', _('Unknown')))
 
             if not os.path.exists(newpath):
                 os.makedirs(newpath)
diff --git a/src/calibre/devices/usbms/driver.py b/src/calibre/devices/usbms/driver.py
index bb7a104fa4..aa40f90c25 100644
--- a/src/calibre/devices/usbms/driver.py
+++ b/src/calibre/devices/usbms/driver.py
@@ -124,8 +124,8 @@ class USBMS(CLI, Device):
                             break
                             
                 if newpath == path:
-                    newpath = os.path.join(newpath, authors_to_string(mdata.get('authors', '')))
-                    newpath = os.path.join(newpath, mdata.get('title', ''))
+                    newpath = os.path.join(newpath, mdata.get('authors', _('Unknown')))
+                    newpath = os.path.join(newpath, mdata.get('title', _('Unknown')))
 
             if not os.path.exists(newpath):
                 os.makedirs(newpath)