diff --git a/share/mk/local.sys.dirdeps.mk b/share/mk/local.sys.dirdeps.mk
index f06b4a33f1f..9fdfab58803 100644
--- a/share/mk/local.sys.dirdeps.mk
+++ b/share/mk/local.sys.dirdeps.mk
@@ -122,7 +122,7 @@ ${var}=		${HOST_${var}}
 FREEBSD_REVISION!= sed -n '/^REVISION=/{s,.*=,,;s,",,g;p; }' ${SRCTOP}/sys/conf/newvers.sh
 .export FREEBSD_REVISION
 .endif
-CROSS_TARGET_FLAGS= -target ${MACHINE_ARCH}-unknown-freebsd${FREEBSD_REVISION}
+CROSS_TARGET_FLAGS?= -target ${MACHINE_ARCH}-unknown-freebsd${FREEBSD_REVISION}
 CFLAGS+= ${CROSS_TARGET_FLAGS}
 ACFLAGS+= ${CROSS_TARGET_FLAGS}
 .endif