--- WebIDL.py
+++ WebIDL.py
@@ -8827,6 +8827,7 @@ class Parser(Tokenizer):
                 module=self,
                 outputdir=outputdir,
                 errorlog=logger,
+                debug=False,
                 write_tables=False,
                 # Pickling the grammar is a speedup in
                 # some cases (older Python?) but a