diff --git a/containers/release/Dockerfile.in b/containers/release/Dockerfile.in
index 3696ffc4bddce643b40ceea4c2f761256d04f9e8..cb21cf8d47ba2b41760752d3ca1fe0bcb2de8cd2 100644
--- a/containers/release/Dockerfile.in
+++ b/containers/release/Dockerfile.in
@@ -35,6 +35,7 @@ RUN apt-get -yqq update \
         ghostscript \
         gv \
         poppler-utils \
+        parallel \
  && apt-get -yqq autoremove \
  && rm -rf /var/lib/apt/lists/*