diff --git a/phplist/Dockerfile b/phplist/Dockerfile
index 24926a4..f768090 100644
--- a/phplist/Dockerfile
+++ b/phplist/Dockerfile
@@ -1,5 +1,5 @@
 
-FROM debian:buster-slim
+FROM debian:bullseye-slim
 
 LABEL maintainer="michiel@phplist.com"