diff --git a/sdk_container/src/third_party/coreos-overlay/profiles/coreos/base/make.defaults b/sdk_container/src/third_party/coreos-overlay/profiles/coreos/base/make.defaults
index 9dcf8cb33b..06889387d5 100644
--- a/sdk_container/src/third_party/coreos-overlay/profiles/coreos/base/make.defaults
+++ b/sdk_container/src/third_party/coreos-overlay/profiles/coreos/base/make.defaults
@@ -102,3 +102,6 @@ DONT_MOUNT_BOOT=1
 
 # Both x86_64 and i386 targets are required for grub testing
 QEMU_SOFTMMU_TARGETS="x86_64 i386 aarch64"
+
+# For cross build support.
+QEMU_USER_TARGETS="aarch64"