diff --git a/src/calibre/srv/cdb.py b/src/calibre/srv/cdb.py
index 9f04e77392..81d86d46d1 100644
--- a/src/calibre/srv/cdb.py
+++ b/src/calibre/srv/cdb.py
@@ -144,6 +144,7 @@ def cdb_set_fields(ctx, rd, book_id, library_id):
         raise HTTPBadRequest('Invalid encoded data')
     try:
         changes, loaded_book_ids = data['changes'], frozenset(map(int, data.get('loaded_book_ids', ())))
+        all_dirtied = bool(data.get('all_dirtied'))
         if not isinstance(changes, dict):
             raise TypeError('changes must be a dict')
     except Exception:
@@ -168,4 +169,6 @@ def cdb_set_fields(ctx, rd, book_id, library_id):
     for field, value in changes.iteritems():
         dirtied |= db.set_field(field, {book_id: value})
     ctx.notify_changes(db.backend.library_path, metadata(dirtied))
-    return {bid: book_as_json(db, book_id) for bid in (dirtied & loaded_book_ids) | {book_id}}
+    all_ids = dirtied if all_dirtied else (dirtied & loaded_book_ids)
+    all_ids |= {book_id}
+    return {bid: book_as_json(db, book_id) for bid in all_ids}