diff --git a/docker.mk b/docker.mk
index 929248a..4ff929a 100644
--- a/docker.mk
+++ b/docker.mk
@@ -29,6 +29,7 @@
 	   -v $(ROOTDIR)\:/build \
 	   -v $(TARBALL_FETCH_ROOT_DIRECTORY)\:/tarballs \
 	   -v $(PREBUILT_DOCKER_ROOT)\:/docker \
+	   -v $(PREBUILT_MODULES_ROOT)\:/modules \
 	   -w /build \
 		 -e "DEBOOTSTRAP_FETCH_TARBALL=$(DEBOOTSTRAP_FETCH_TARBALL)" \
 		 -e "ROOTFS_FETCH_TARBALL=$(ROOTFS_FETCH_TARBALL)" \
@@ -36,7 +37,7 @@
 		 -e "PREBUILT_DOCKER_ROOT=/docker" \
 		 -e "ROOTFS_REVISION=$(ROOTFS_REVISION)" \
 		 -e "DEBOOTSTRAP_TARBALL_REVISION=$(DEBOOTSTRAP_TARBALL_REVISION)" \
-		 -e "PREBUILT_MODULES_ROOT=$(PREBUILT_MODULES_ROOT)" \
+		 -e "PREBUILT_MODULES_ROOT=/modules" \
 	   aiy-board-builder \
 	   /bin/bash -c \
 	   'groupadd --gid $$(shell id -g) $$(shell id -g -n); \