diff --git a/sys/conf/kern.mk b/sys/conf/kern.mk
index 2939a59cb0b4..6e6ba92c4db5 100644
--- a/sys/conf/kern.mk
+++ b/sys/conf/kern.mk
@@ -147,6 +147,12 @@ INLINE_LIMIT?=	8000
 #
 CFLAGS+=	-ffreestanding
 
+#
+# Do not allow a compiler to optimize out overflow checks for signed
+# types.
+#
+CFLAGS+=	-fno-strict-overflow
+
 #
 # GCC SSP support
 #