diff --git a/scripts/lilypond-book.py b/scripts/lilypond-book.py
index ac3969c..1f8a010 100644
--- a/scripts/lilypond-book.py
+++ b/scripts/lilypond-book.py
@@ -1205,7 +1205,7 @@ left-margin-default right-margin-default)"
         option_list = []
         for option in self.get_option_list ():
             for name in PROCESSING_INDEPENDENT_OPTIONS:
-                if not option.startswith (name):
+                if option.startswith (name):
                     option_list.append (option)
         option_string = ','.join (option_list)