diff --git a/src/calibre/devices/prs505/__init__.py b/src/calibre/devices/prs505/__init__.py
index 48b7d98123..1a59cb81a6 100644
--- a/src/calibre/devices/prs505/__init__.py
+++ b/src/calibre/devices/prs505/__init__.py
@@ -8,5 +8,5 @@ CACHE_XML = 'Sony Reader/database/cache.xml'
 CACHE_EXT = 'Sony Reader/database/cacheExt.xml'
 
 MEDIA_THUMBNAIL = 'database/thumbnail'
-CACHE_THUMBNAIL = 'Sony Reader/database/thumbnail'
+CACHE_THUMBNAIL = 'Sony Reader/thumbnail'