diff --git a/ci/images/debian/Dockerfile.ruby34 b/ci/images/debian/Dockerfile.ruby34
index 6ddccac84..f0cc157b0 100644
--- a/ci/images/debian/Dockerfile.ruby34
+++ b/ci/images/debian/Dockerfile.ruby34
@@ -1,5 +1,5 @@
 # Base-image
-FROM ruby:3.4.6-slim-trixie AS base
+FROM ruby:3.4.7-slim-trixie@sha256:2de50c072bed1bdaf5e6b6c132fb2bc56f03700046ad95a515b4111203bf5034 AS base
 
 ARG DEBIAN_REPO
 ARG GITHUB_RAW_URL=https://raw.githubusercontent.com