-RUN apt-get install -yq --no-install-recommends \
- git python-pip python-virtualenv \
- python-dev libgnutls28-dev libcurl4-gnutls-dev nodejs \
- python-arvados-python-client=$python_sdk_version \
- python-arvados-cwl-runner=$cwl_runner_version
+RUN apt-get install -yq --no-install-recommends python3-arvados-cwl-runner=$cwl_runner_version
+
+# use the Python executable from the python-arvados-cwl-runner package
+RUN PYTHON=`ls /usr/share/python3*/dist/python3-arvados-cwl-runner/bin/python|head -n1` && rm -f /usr/bin/python && ln -s $PYTHON /usr/bin/python
+RUN PYTHON3=`ls /usr/share/python3*/dist/python3-arvados-cwl-runner/bin/python3|head -n1` && rm -f /usr/bin/python3 && ln -s $PYTHON3 /usr/bin/python3