diff --git a/usr.sbin/acpi/iasl/Makefile b/usr.sbin/acpi/iasl/Makefile
index 6b95cc1d745..3a490962f21 100644
--- a/usr.sbin/acpi/iasl/Makefile
+++ b/usr.sbin/acpi/iasl/Makefile
@@ -81,6 +81,8 @@ WARNS?=	2
 MAN=	iasl.8
 
 CFLAGS+= -DACPI_ASL_COMPILER -I.
+CWARNFLAGS.aslrestype2s.c= ${NO_WUNUSED_BUT_SET_VARIABLE}
+CWARNFLAGS.dmextern.c= ${NO_WUNUSED_BUT_SET_VARIABLE}
 LFLAGS= -i -s
 DLFLAGS=-i
 YFLAGS= -d