diff --git a/sys/conf/kern.mk b/sys/conf/kern.mk
--- a/sys/conf/kern.mk
+++ b/sys/conf/kern.mk
@@ -6,7 +6,7 @@
 		-Wmissing-prototypes -Wpointer-arith -Wcast-qual \
 		-Wundef -Wno-pointer-sign ${FORMAT_EXTENSIONS} \
 		-Wmissing-include-dirs -fdiagnostics-show-option \
-		-Wno-unknown-pragmas \
+		-Wno-unknown-pragmas -Wswitch \
 		${CWARNEXTRA}
 #
 # The following flags are next up for working on: