diff --git a/docker.mk b/docker.mk
index 3557402..a321f38 100644
--- a/docker.mk
+++ b/docker.mk
@@ -48,6 +48,7 @@
 	   -w /build \
 		 -e "DEBOOTSTRAP_FETCH_TARBALL=$(DEBOOTSTRAP_FETCH_TARBALL)" \
 		 -e "ROOTFS_FETCH_TARBALL=$(ROOTFS_FETCH_TARBALL)" \
+		 -e "ARM64_BUILDER_FETCH_TARBALL=$(ARM64_BUILDER_FETCH_TARBALL)" \
 		 -e "TARBALL_FETCH_ROOT_DIRECTORY=/tarballs" \
 		 -e "PREBUILT_DOCKER_ROOT=/docker" \
 		 -e "ROOTFS_REVISION=$(ROOTFS_REVISION)" \