diff --git a/Dockerfile b/Dockerfile
index 938badc..99d8709 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -59,9 +59,9 @@ COPY --chmod=755 ./src /run/
 VOLUME /storage
 EXPOSE 22 5900 8006
 
+ENV BOOT="alpine"
 ENV CPU_CORES="2"
 ENV RAM_SIZE="2G"
 ENV DISK_SIZE="16G"
-ENV BOOT="http://example.com/image.iso"
 
 ENTRYPOINT ["/usr/bin/tini", "-s", "/run/entry.sh"]