diff --git a/slapd/Dockerfile b/slapd/Dockerfile
index 508aadef4e5986b0eec50740bfed2489c730c976..8f39876f053260eabd280faf57471fa72d234751 100644
--- a/slapd/Dockerfile
+++ b/slapd/Dockerfile
@@ -1,4 +1,4 @@
-FROM debian:buster-slim
+FROM debian:bullseye-slim
 # hadolint ignore=DL3008
 RUN apt-get update && \
     DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \