diff --git a/Dockerfile.ubuntu b/Dockerfile.ubuntu
index 3f8bd86..0e8e166 100644
--- a/Dockerfile.ubuntu
+++ b/Dockerfile.ubuntu
@@ -3,7 +3,11 @@ ARG BASE_TAG="24.04"
 
 FROM ${BASE_REPO}ubuntu:${BASE_TAG}
 
-RUN apt update
-RUN apt install -y --no-install-recommends ca-certificates
+RUN <<EOF
+    set -eux
+    apt update
+    apt install -y --no-install-recommends ca-certificates
+    rm -rf /var/lib/apt/lists/*
+EOF
 
 COPY apt/ubuntu.sources /etc/apt/sources.list.d/ubuntu.sources