diff --git a/src/calibre/devices/kobo/driver.py b/src/calibre/devices/kobo/driver.py
index 2c8a77c454..b5d39cda7e 100644
--- a/src/calibre/devices/kobo/driver.py
+++ b/src/calibre/devices/kobo/driver.py
@@ -69,7 +69,7 @@ class KOBO(USBMS):
 
     dbversion = 0
     fwversion = (0,0,0)
-    supported_dbversion = 129
+    supported_dbversion = 146
     has_kepubs = False
 
     supported_platforms = ['windows', 'osx', 'linux']
@@ -1316,7 +1316,7 @@ class KOBOTOUCH(KOBO):
                     ' Based on the existing Kobo driver by %s.') % KOBO.author
 #    icon        = I('devices/kobotouch.jpg')
 
-    supported_dbversion             = 143
+    supported_dbversion             = 146
     min_supported_dbversion         = 53
     min_dbversion_series            = 65
     min_dbversion_externalid        = 65
@@ -1328,7 +1328,7 @@ class KOBOTOUCH(KOBO):
     # Starting with firmware version 3.19.x, the last number appears to be is a
     # build number. A number will be recorded here but it can be safely ignored
     # when testing the firmware version.
-    max_supported_fwversion         = (4, 7, 10413)
+    max_supported_fwversion         = (4, 8, 10956)
     # The following document firwmare versions where new function or devices were added.
     # Not all are used, but this feels a good place to record it.
     min_fwversion_shelves           = (2, 0, 0)
@@ -1337,8 +1337,9 @@ class KOBOTOUCH(KOBO):
     min_aurah2o_fwversion           = (3, 7, 0)
     min_reviews_fwversion           = (3, 12, 0)
     min_glohd_fwversion             = (3, 14, 0)
-    min_auraone_fwversion           = (3, 20, 7280)
-    min_fwversion_overdrive         = (4,  0, 7523)
+    min_auraone_fwversion           = (3, 20,  7280)
+    #min_clarahd_fwversion           = (4,  8, 10956) # It is coming, this is probably the firmware, but I don't have any ids for it.
+    min_fwversion_overdrive         = (4,  0,  7523)
 
     has_kepubs = True
 
@@ -2039,7 +2040,8 @@ class KOBOTOUCH(KOBO):
 #                        debug_print('KoboTouch:upload_books: Delete record left if deleted on Touch')
                         cursor.execute(cleanup_query, cleanup_values)
 
-                        self.set_filesize_in_device_database(connection, contentID, fname)
+                        if self.override_kobo_replace_existing:
+                            self.set_filesize_in_device_database(connection, contentID, fname)
 
                         if not self.upload_covers:
                             imageID = self.imageid_from_contentid(contentID)
@@ -2963,6 +2965,7 @@ class KOBOTOUCH(KOBO):
         c.add_opt('update_device_metadata', default=True)
 
         c.add_opt('modify_css', default=False)
+        c.add_opt('override_kobo_replace_existing', default=True) # Overriding the replace behaviour is how the driver has always worked.
 
         c.add_opt('support_newer_firmware', default=False)
         c.add_opt('debugging_title', default='')
@@ -3124,6 +3127,10 @@ class KOBOTOUCH(KOBO):
     def modifying_css(self):
         return self.get_pref('modify_css')
 
+    @property
+    def override_kobo_replace_existing(self):
+        return self.get_pref('override_kobo_replace_existing')
+
     @property
     def update_device_metadata(self):
         return self.get_pref('update_device_metadata')
diff --git a/src/calibre/devices/kobo/kobotouch_config.py b/src/calibre/devices/kobo/kobotouch_config.py
index a4cecd011a..fa14ca17aa 100644
--- a/src/calibre/devices/kobo/kobotouch_config.py
+++ b/src/calibre/devices/kobo/kobotouch_config.py
@@ -114,6 +114,7 @@ class KOBOTOUCHConfig(TabbedDeviceConfig):
 
         p['update_series'] = self.update_series
         p['modify_css'] = self.modify_css
+        p['override_kobo_replace_existing'] = self.override_kobo_replace_existing
 
         p['support_newer_firmware'] = self.support_newer_firmware
         p['debugging_title'] = self.debugging_title
@@ -185,14 +186,30 @@ class BookUploadsGroupBox(DeviceOptionsGroupBox):
                 'these are removed for all styles in the original stylesheet.').format(device.KOBO_EXTRA_CSSFILE),
                 device.get_pref('modify_css')
                 )
+        self.override_kobo_replace_existing_checkbox = create_checkbox(
+                _("Override Kobo's default book replacement behavior"),
+                _('When a new book is sideloaded, the Kobo firmware imports details of the book into the internal database. '
+                'If the book is replaced, the firmware will remove the book from the database and then treat it as a new book. '
+                'This will meant the reading status, bookmarks and collections for the book will be lost. '
+                'This option overrides firmware behavior and attempts to prevent a book that has been resent from being treated as a new books. '
+                'This has been doing this since driver version 2.0.0 but has not had the option to allow the default firmware behaviour.' 
+                ),
+                device.get_pref('override_kobo_replace_existing')
+                )
+
 
         self.options_layout.addWidget(self.modify_css_checkbox, 0, 0, 1, 2)
-        self.options_layout.setRowStretch(1, 1)
+        self.options_layout.addWidget(self.override_kobo_replace_existing_checkbox, 1, 0, 1, 2)
+        self.options_layout.setRowStretch(2, 1)
 
     @property
     def modify_css(self):
         return self.modify_css_checkbox.isChecked()
 
+    @property
+    def override_kobo_replace_existing(self):
+        return self.override_kobo_replace_existing_checkbox.isChecked()
+
 
 class CollectionsGroupBox(DeviceOptionsGroupBox):