diff --git a/src/calibre/ebooks/metadata/book/__init__.py b/src/calibre/ebooks/metadata/book/__init__.py
index c106582bfa..39fb1920cd 100644
--- a/src/calibre/ebooks/metadata/book/__init__.py
+++ b/src/calibre/ebooks/metadata/book/__init__.py
@@ -90,7 +90,6 @@ CALIBRE_METADATA_FIELDS = frozenset([
 
 CALIBRE_RESERVED_LABELS = frozenset([
     'all',          # search term
-    'author_sort',  # can appear in device collection customization
     'date',         # search term
     'formats',      # search term
     'inlibrary',    # search term