diff --git a/parse.y b/parse.y
index f6b32d5c97..526a25ac3b 100644
--- a/parse.y
+++ b/parse.y
@@ -9,6 +9,8 @@
 
 **********************************************************************/
 
+%require "3.0"
+
 %{
 
 #if !YYPURE