Index: head/Makefile
===================================================================
--- head/Makefile
+++ head/Makefile
@@ -374,6 +374,17 @@
 #
 .if make(universe) || make(universe_kernels) || make(tinderbox) || make(targets)
 TARGETS?=amd64 arm i386 mips pc98 powerpc sparc64
+# XXX Add arm64 to universe only if we have an external binutils installed.
+# It does not build with the in-tree linnker.
+.if exists(/usr/local/aarch64-freebsd/bin/ld)
+TARGETS+=arm64
+TARGET_ARCHES_arm64?=	aarch64
+.else
+universe: universe_arm64_skip
+universe_epilogue: universe_arm64_skip
+universe_arm64_skip: universe_prologue
+	@echo ">> arm64 skipped - install aarch64-binutils port or package to build"
+.endif
 TARGET_ARCHES_arm?=	arm armeb armv6 armv6hf
 TARGET_ARCHES_mips?=	mipsel mips mips64el mips64 mipsn32
 TARGET_ARCHES_powerpc?=	powerpc powerpc64