diff --git a/src/calibre/devices/cybookg3/driver.py b/src/calibre/devices/cybookg3/driver.py
index 6a77c09479..0a9d69f7a9 100644
--- a/src/calibre/devices/cybookg3/driver.py
+++ b/src/calibre/devices/cybookg3/driver.py
@@ -7,6 +7,7 @@ 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 FreeSpaceError
 from calibre.devices.usbms.driver import USBMS
 import calibre.devices.cybookg3.t2b as t2b
@@ -84,7 +85,7 @@ class CYBOOKG3(USBMS):
                             break
                             
                 if newpath == path:
-                    newpath = os.path.join(newpath, mdata.get('authors', ''))
+                    newpath = os.path.join(newpath, authors_to_string(mdata.get('authors', '')))
                     newpath = os.path.join(newpath, mdata.get('title', ''))
 
             if not os.path.exists(newpath):
diff --git a/src/calibre/devices/usbms/driver.py b/src/calibre/devices/usbms/driver.py
index a088bf1a32..06bfa243f1 100644
--- a/src/calibre/devices/usbms/driver.py
+++ b/src/calibre/devices/usbms/driver.py
@@ -115,7 +115,7 @@ class USBMS(Device):
                             break
                             
                 if newpath == path:
-                    newpath = os.path.join(newpath, mdata.get('authors', ''))
+                    newpath = os.path.join(newpath, authors_to_string(mdata.get('authors', '')))
                     newpath = os.path.join(newpath, mdata.get('title', ''))
 
             if not os.path.exists(newpath):