--- Source/WebCore/css/CSSGrammar.y.in.orig	2020-03-04 17:16:37 UTC
+++ Source/WebCore/css/CSSGrammar.y.in
@@ -21,7 +21,7 @@
  *
  */
 
-%pure-parser
+%define api.pure
 
 %parse-param { CSSParser* parser }
 %lex-param { CSSParser* parser }