diff --git a/src/calibre/devices/kindle/driver.py b/src/calibre/devices/kindle/driver.py
index 3c875ba9d9..3ce69dba1e 100644
--- a/src/calibre/devices/kindle/driver.py
+++ b/src/calibre/devices/kindle/driver.py
@@ -170,8 +170,8 @@ class KINDLE2(KINDLE):
     name           = 'Kindle 2/3 Device Interface'
     description    = _('Communicate with the Kindle 2/3 eBook reader.')
 
-    FORMATS        = KINDLE.FORMATS + ['pdf']
-    DELETE_EXTS    = KINDLE.DELETE_EXTS + ['.apnx']
+    FORMATS        = KINDLE.FORMATS + ['pdf', 'azw4']
+    DELETE_EXTS    = KINDLE.DELETE_EXTS
 
     PRODUCT_ID = [0x0002, 0x0004]
     BCD        = [0x0100]