diff --git a/Makefile.local b/Makefile.local
index 2431531..7ffbed4 100644
--- a/Makefile.local
+++ b/Makefile.local
@@ -37,7 +37,8 @@
 # You can append to an existing Makefile variable using '+=' symbols.
 # For example:
 #
-#	CFLAGS+= -Ofast
+#	CCOPT+= -Ofast
+#	COMMON_CFLAGS+= -std=gnu2x
 ####
 
 ###################################################################