diff --git a/contrib/create-coreos-vdi b/contrib/create-coreos-vdi
index 320e889262..3cd58daded 100755
--- a/contrib/create-coreos-vdi
+++ b/contrib/create-coreos-vdi
@@ -113,7 +113,7 @@ echo "Writing ${IMAGE_NAME} to ${DOWN_IMAGE}..."
 bzcat -v --stdout "${WORKDIR}/${IMAGE_NAME}" >"${DOWN_IMAGE}"
 
 echo "Converting ${RAW_IMAGE_NAME} to VirtualBox format..."
-VBoxManage convertdd ${DOWN_IMAGE} ${VDI_IMAGE} --format VDI
+VBoxManage convertdd "${DOWN_IMAGE}" "${VDI_IMAGE}" --format VDI
 
 rm -rf "${WORKDIR}"
 trap - EXIT