diff --git a/ansible/tljh.yml b/ansible/tljh.yml
index 5c46e01..9592c85 100644
--- a/ansible/tljh.yml
+++ b/ansible/tljh.yml
@@ -46,6 +46,7 @@
     # Pull the repo2docker image to build user images
     - name: Pull the repo2docker Docker image
       docker_image:
-        name: quay.io/jupyterhub/repo2docker
-        tag: main
+        name: "{{ repo2docker_docker_name }}"
+        tag: "{{ repo2docker_docker_tag }}"
         source: pull
+        force_source: yes
diff --git a/ansible/vars/default.yml b/ansible/vars/default.yml
index 2d992cd..eb9fa4f 100644
--- a/ansible/vars/default.yml
+++ b/ansible/vars/default.yml
@@ -9,4 +9,7 @@ tljh_prefix: /opt/tljh
 tljh_bootstrap_pip_spec: git+https://github.com/jtpio/the-littlest-jupyterhub.git@skip-install#"egg=the_littlest_jupyterhub"
 tljh_installer_url: https://raw.githubusercontent.com/jtpio/the-littlest-jupyterhub/skip-install/bootstrap/bootstrap.py
 
+repo2docker_docker_name: quay.io/jupyterhub/repo2docker
+repo2docker_docker_tag: 2023.06.0-41.g57d229e
+
 ...
diff --git a/docs/install/ansible.md b/docs/install/ansible.md
index ce64c02..bd1bb5c 100644
--- a/docs/install/ansible.md
+++ b/docs/install/ansible.md
@@ -268,6 +268,21 @@ tagged as `v0.1`:
 tljh_plasma: git+https://github.com/plasmabio/plasma@v0.1#"egg=tljh-plasma&subdirectory=tljh-plasma"
 ```
 
+## Using a specific version of `repo2docker`
+
+`repo2docker` is used to build the user environments from the Git repositories.
+
+By default the Ansible playbooks use a pinned version of the `jupyterhub/repo2docker`, which is defined in the
+`ansible/vars/default.yml` file.
+
+Like other Ansible variables, it is possible to use a different version of `repo2docker` by overriding the variable
+via the command line:
+
+```bash
+# use an older version of the repo2docker image
+ansible-playbook tljh.yml -i hosts -u ubuntu -e "repo2docker_docker_tag=2022.10.0-232.g0ea6f7d"
+```
+
 ## List of available playbooks
 
 The Ansible playbooks are located in the `ansible/` directory:
diff --git a/tljh-plasma/tljh_plasma/__init__.py b/tljh-plasma/tljh_plasma/__init__.py
index ff067bb..60f2ffc 100644
--- a/tljh-plasma/tljh_plasma/__init__.py
+++ b/tljh-plasma/tljh_plasma/__init__.py
@@ -123,6 +123,8 @@ def tljh_custom_jupyterhub_config(c, tljh_config_file=CONFIG_FILE):
     c.PlasmaSpawner.cmd = ["/srv/conda/envs/notebook/bin/jupyterhub-singleuser"]
     # set the default cpu and memory limits
     c.PlasmaSpawner.args = ["--ResourceUseDisplay.track_cpu_percent=True"]
+    # explicitely opt-in to enable the custom entrypoint logic
+    c.PlasmaSpawner.run_as_root = True
 
     # prevent PID 1 running in the Docker container to stop when child processes are killed
     # see https://github.com/plasmabio/plasma/issues/191 for more info
diff --git a/tljh-plasma/tljh_plasma/entrypoint/entrypoint.sh b/tljh-plasma/tljh_plasma/entrypoint/entrypoint.sh
index e9a66d8..0a91c1c 100755
--- a/tljh-plasma/tljh_plasma/entrypoint/entrypoint.sh
+++ b/tljh-plasma/tljh_plasma/entrypoint/entrypoint.sh
@@ -43,4 +43,4 @@ export JUPYTER_PATH=${IMAGE_DIR}/.local/share/jupyter
 cd ${IMAGE_DIR}
 
 # execute the notebook process as the given user
-exec su - $NB_USER -m -c '"$0" "$@"' -- "$@"
+exec su $NB_USER -m -c '"$0" "$@"' -- "$@"