diff --git a/docker/Dockerfile b/docker/Dockerfile
index 411ac67..918b89c 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -1,58 +1,59 @@
 FROM python:3.7
 
 RUN . /etc/os-release && echo "deb http://apt.postgresql.org/pub/repos/apt ${VERSION_CODENAME}-pgdg main" > /etc/apt/sources.list.d/pgdg.list && \
   wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | apt-key add - && \
   echo "deb [signed-by=/usr/share/keyrings/nodejs-archive-keyring.gpg] https://deb.nodesource.com/node_12.x ${VERSION_CODENAME} main" > /etc/apt/sources.list.d/nodejs.list && \
   curl -fsSL https://deb.nodesource.com/gpgkey/nodesource.gpg.key | gpg --dearmor > /usr/share/keyrings/nodejs-archive-keyring.gpg && \
   echo "deb [signed-by=/usr/share/keyrings/yarnpkg-archive-keyring.gpg] https://dl.yarnpkg.com/debian/ stable main" > /etc/apt/sources.list.d/yarnpkg.list && \
   curl -fsSL https://dl.yarnpkg.com/debian/pubkey.gpg | gpg --dearmor > /usr/share/keyrings/yarnpkg-archive-keyring.gpg
 
 RUN export DEBIAN_FRONTEND=noninteractive && \
   apt-get update && apt-get upgrade -y && \
   apt-get install -y \
     libapr1-dev \
     libaprutil1-dev \
     libpq-dev \
     libsvn-dev \
     libsystemd-dev \
     memcached \
     postgresql-client-12 \
     wait-for-it \
     ngrep \
     rsync \
     nodejs \
     yarn && \
   apt-get install -y --no-install-recommends \
+    opam \
     r-base-core \
     r-cran-jsonlite && \
   apt-get clean && \
   rm -rf /var/lib/apt/lists/*
 
 RUN useradd -md /srv/softwareheritage -s /bin/bash swh
 USER swh
 
 RUN python3 -m venv /srv/softwareheritage/venv
 ENV PATH="/srv/softwareheritage/venv/bin:${PATH}"
 RUN pip install --upgrade pip setuptools wheel
 RUN pip install gunicorn httpie
 
 RUN pip install \
         swh-core[db,http] \
         swh-counters \
         swh-deposit[server] \
         swh-indexer \
         swh-journal \
         swh-lister \
         swh-loader-core \
         swh-loader-git \
         swh-loader-mercurial \
         swh-loader-svn \
         swh-storage \
         swh-objstorage \
         swh-scheduler \
         swh-vault \
         swh-web
 
 COPY utils/*.sh /srv/softwareheritage/utils/
 RUN mkdir -p /srv/softwareheritage/objects
 RUN rm -rd /srv/softwareheritage/.cache