--- a/taskcluster/taskgraph/transforms/tests/make_task_description.py
+++ b/taskcluster/taskgraph/transforms/tests/make_task_description.py
@@ -183,18 +183,24 @@ def docker_worker_setup(config, test, ta
             'mount-point': '/home/worker/tooltool-cache',
         })
         taskdesc['scopes'].extend([
             'docker-worker:relengapi-proxy:tooltool.download.internal',
             'docker-worker:relengapi-proxy:tooltool.download.public',
         ])
 
     # assemble the command line
+    command = [
+        '/home/worker/bin/run-task',
+        # The workspace cache/volume is default owned by root:root.
+        '--chown', '/home/worker/workspace',
+        '--',
+        '/home/worker/bin/test-linux.sh',
+    ]
 
-    command = ["bash", "/home/worker/bin/test.sh"]
     if mozharness.get('no-read-buildbot-config'):
         command.append("--no-read-buildbot-config")
     command.extend([
         {"task-reference": "--installer-url=" + installer_url},
         {"task-reference": "--test-packages-url=" + test_packages_url},
     ])
     command.extend(mozharness.get('extra-options', []))
 

--- a/testing/docker/desktop-test/Dockerfile
+++ b/testing/docker/desktop-test/Dockerfile
@@ -37,17 +37,16 @@ ENV           USER          worker
 ENV           LOGNAME       worker
 ENV           HOSTNAME      taskcluster-worker
 ENV           LANG          en_US.UTF-8
 ENV           LC_ALL        en_US.UTF-8
 
 # Add utilities and configuration
 COPY           dot-files/config              /home/worker/.config
 COPY           dot-files/pulse               /home/worker/.pulse
-COPY           bin                           /home/worker/bin
 RUN            chmod +x bin/*
 # TODO: remove this when buildbot is gone
 COPY           buildprops.json               /home/worker/buildprops.json
 COPY           tc-vcs-config.yml /etc/taskcluster-vcs.yml
 
 # TODO: remove
 ADD            https://raw.githubusercontent.com/taskcluster/buildbot-step/master/buildbot_step /home/worker/bin/buildbot_step
 RUN chmod u+x /home/worker/bin/buildbot_step

deleted file mode 100644
--- a/testing/docker/desktop-test/bin/test.sh
+++ /dev/null
@@ -1,20 +0,0 @@
-#! /bin/bash -vex
-
-set -x -e
-
-: GECKO_HEAD_REPOSITORY         ${GECKO_HEAD_REPOSITORY:=https://hg.mozilla.org/mozilla-central}
-: GECKO_HEAD_REV                ${GECKO_HEAD_REV:=default}
-: WORKSPACE                     ${WORKSPACE:=/home/worker/workspace}
-
-
-# TODO: when bug 1093833 is solved and tasks can run as non-root, reduce this
-# to a simple fail-if-root check
-if [ $(id -u) = 0 ]; then
-    chown -R worker:worker /home/worker
-    # drop privileges by re-running this script
-    exec sudo -E -u worker bash /home/worker/bin/test.sh "${@}"
-fi
-
-[ -d $WORKSPACE ] || mkdir -p $WORKSPACE
-cd $WORKSPACE
-exec /home/worker/bin/test-linux.sh "${@}"

deleted file mode 100644
--- a/testing/docker/desktop1604-test/bin/test.sh
+++ /dev/null
@@ -1,20 +0,0 @@
-#! /bin/bash -vex
-
-set -x -e
-
-: GECKO_HEAD_REPOSITORY         ${GECKO_HEAD_REPOSITORY:=https://hg.mozilla.org/mozilla-central}
-: GECKO_HEAD_REV                ${GECKO_HEAD_REV:=default}
-: WORKSPACE                     ${WORKSPACE:=/home/worker/workspace}
-
-
-# TODO: when bug 1093833 is solved and tasks can run as non-root, reduce this
-# to a simple fail-if-root check
-if [ $(id -u) = 0 ]; then
-    chown -R worker:worker /home/worker
-    # drop privileges by re-running this script
-    exec sudo -E -u worker bash /home/worker/bin/test.sh "${@}"
-fi
-
-[ -d $WORKSPACE ] || mkdir -p $WORKSPACE
-cd $WORKSPACE
-exec /home/worker/bin/test-linux.sh "${@}"