diff --git a/Dockerfile b/Dockerfile
index 1dabc9c..76c4853 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -13,7 +13,7 @@ RUN xvfb-run sh /tmp/helper/wine-init.sh
 # renovate: datasource=github-tags depName=python/cpython versioning=pep440
 ARG PYTHON_VERSION=3.12.0
 # renovate: datasource=github-releases depName=upx/upx versioning=loose
-ARG UPX_VERSION=4.0.2
+ARG UPX_VERSION=4.2.1
 
 RUN umask 0 && cd /tmp/helper && \
   curl -LOOO \
diff --git a/SHA256SUMS.txt b/SHA256SUMS.txt
index fb9fe31..3696a4e 100644
--- a/SHA256SUMS.txt
+++ b/SHA256SUMS.txt
@@ -1 +1 @@
-325c58ea2ed375afbd4eeac0b26f15f98db0d75dea701205ca10d8bf4d2fdc24  upx-4.0.2-win64.zip
+b6e20e35303a390c3b1211f5ed0559def2c34ec5774176bb22afee19b35b2138  upx-4.2.1-win64.zip