diff --git a/Dockerfile b/Dockerfile
index 097e93c..ac18744 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:focal
+FROM mirror.gcr.io/library/ubuntu:focal
 RUN apt-get update \
  && apt-get install -y \
     curl ca-certificates iputils-ping \