diff --git a/nest/config.Y b/nest/config.Y
index 1c40ced6..ce45d98d 100644
--- a/nest/config.Y
+++ b/nest/config.Y
@@ -154,7 +154,7 @@ CF_ENUM_PX(T_ENUM_AF, AF_, AFI_, IPV4, IPV6)
 
 CF_GRAMMAR
 
-kw_sym: MIN MAX ;
+kw_sym: MIN | MAX ;
 
 /* Setting of router ID */