diff --git a/Dockerfile b/Dockerfile
index f6fc1499..76deb0f8 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,5 +1,5 @@
  # 3.1.3-buster
-FROM ruby@sha256:55cd5fab4140db7a04f46921eafcd941be95f6c5687b01154d43e75479ba0fe9
+FROM ruby@sha256:9afef279599922a4426c91d0a2a0d0c32c15ef0f65490ae83132a683d58ab978
 
 EXPOSE 4567:4567
 EXPOSE 35729:35729