diff --git a/testdata/acceptance/deb.dockerfile b/testdata/acceptance/deb.dockerfile
index a761a54..208963e 100644
--- a/testdata/acceptance/deb.dockerfile
+++ b/testdata/acceptance/deb.dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu AS test_base
+FROM ubuntu:20.04 AS test_base
 ARG package
 RUN echo "${package}"
 COPY ${package} /tmp/foo.deb