diff --git a/sys/conf/kern.mk b/sys/conf/kern.mk
--- a/sys/conf/kern.mk
+++ b/sys/conf/kern.mk
@@ -74,8 +74,7 @@
 		-Wno-error=sequence-point			\
 		-Wno-error=shift-overflow			\
 		-Wno-error=tautological-compare			\
-		-Wno-error=unused-function			\
-		-Wno-unused-but-set-variable
+		-Wno-error=unused-function
 .if ${COMPILER_VERSION} >= 70100
 CWARNEXTRA+=	-Wno-error=stringop-overflow
 .endif