diff --git a/src/calibre/gui2/actions/add.py b/src/calibre/gui2/actions/add.py
index 379e72822d..08385f4f3f 100644
--- a/src/calibre/gui2/actions/add.py
+++ b/src/calibre/gui2/actions/add.py
@@ -33,8 +33,8 @@ def get_filters():
             (_('LIT Books'), ['lit']),
             (_('MOBI Books'), ['mobi', 'prc', 'azw']),
             (_('Topaz books'), ['tpz','azw1']),
-            (_('Text books'), ['txt', 'rtf']),
-            (_('PDF Books'), ['pdf']),
+            (_('Text books'), ['txt', 'text', 'rtf']),
+            (_('PDF Books'), ['pdf', 'azw4']),
             (_('SNB Books'), ['snb']),
             (_('Comics'), ['cbz', 'cbr', 'cbc']),
             (_('Archives'), ['zip', 'rar']),