--- a/src/usr.sbin/kldxref/Makefile
+++ b/src/usr.sbin/kldxref/Makefile
@@ -7,6 +7,8 @@
 WARNS?=	2
 CFLAGS+=-fno-strict-aliasing
 
+LDADD+=	-lbsd
+
 .if exists(ef_${MACHINE_CPUARCH}.c) && ${MACHINE_ARCH} != "powerpc64"
 SRCS+=	ef_${MACHINE_CPUARCH}.c
 .else