diff --git a/CHANGELOG.md b/CHANGELOG.md
index 93dbf5c..e33c7ea 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,9 @@ Changelog", this file is a reverse-chronological list of merged pull requests.
 
 ## Open PR's
 
+- [PR-155](https://github.com/itk-dev/devops_itkdev-docker/pull/155) - 2026-10-05 -
+  Python template: select the services to lint and test by the label
+  `dk.itkdev.language: python` instead of `dk.itkdev.python: "true"`
 - [PR-154](https://github.com/itk-dev/devops_itkdev-docker/pull/154) - 2026-10-05 -
   Pass `github.base_ref` to the changelog workflow through `env` instead of
   interpolating it into the shell command
diff --git a/templates/python/.github/workflows/README.md b/templates/python/.github/workflows/README.md
index 834c387..294840b 100644
--- a/templates/python/.github/workflows/README.md
+++ b/templates/python/.github/workflows/README.md
@@ -21,9 +21,25 @@ reading `docker-compose.yml` (`docker compose config`) and picking every service
 services:
   api:
     labels:
-      dk.itkdev.python: "true"
+      dk.itkdev.language: python
 ```
 
+The label names the language whose checks run in the service, not how the service runs (e.g. `uvicorn` or a CLI),
+so templates for other languages can select their services the same way (`dk.itkdev.language: php`).
+
+How the service runs could later get a label of its own, `dk.itkdev.runtime`, once a template or tool needs to tell
+runtimes apart, e.g. `php-fpm` and `frankenphp` for PHP, or `uvicorn` and `cli` for Python:
+
+```yaml
+services:
+  app:
+    labels:
+      dk.itkdev.language: php
+      dk.itkdev.runtime: frankenphp
+```
+
+Nothing reads `dk.itkdev.runtime` yet.
+
 Every job runs once per service, and each service shows up as its own check, e.g. `Tests (api)`. If no service
 has the label, the workflows fail.
 
@@ -49,7 +65,7 @@ The value must be valid JSON (double quotes). The variable lives in GitHub, not
 1. `.env.example` exists and contains every variable `docker-compose.yml` requires. The workflows copy it to `.env`.
 2. `docker-compose.yml` uses `APP_UID`/`APP_GID` for the container user and an external network named `frontend`;
    both are set up by the workflows.
-3. Each Python service (labelled, or listed in `PYTHON_SERVICES`) can run with `--no-deps` and has `uv`, `pytest` with
+3. Each Python service (labeled, or listed in `PYTHON_SERVICES`) can run with `--no-deps` and has `uv`, `pytest` with
    [pytest-cov](https://pytest-cov.readthedocs.io/), `ruff` and `basedpyright` available.
 4. Coverage is configured in `pyproject.toml` (`[tool.coverage.run] source = [...]`), since the workflow runs
    plain `pytest --cov`.
diff --git a/templates/python/.github/workflows/lint.yml b/templates/python/.github/workflows/lint.yml
index 6ad6007..b710ade 100644
--- a/templates/python/.github/workflows/lint.yml
+++ b/templates/python/.github/workflows/lint.yml
@@ -1,6 +1,6 @@
 name: Python linting
 
-# Checks run in every docker compose service labelled dk.itkdev.python=true.
+# Checks run in every docker compose service labeled dk.itkdev.language=python.
 # The repository variable PYTHON_SERVICES (JSON list, e.g. ["api", "worker"])
 # overrides this.
 
@@ -34,8 +34,8 @@ jobs:
       - id: find
         run: |
           list=$(docker compose config --format json \
-            | jq -c '[.services | to_entries[] | select(.value.labels["dk.itkdev.python"] == "true") | .key]')
-          [ "$list" != "[]" ] || { echo "::error::No service has the label dk.itkdev.python=true"; exit 1; }
+            | jq -c '[.services | to_entries[] | select(.value.labels["dk.itkdev.language"] == "python") | .key]')
+          [ "$list" != "[]" ] || { echo "::error::No service has the label dk.itkdev.language=python"; exit 1; }
           echo "list=$list" >> "$GITHUB_OUTPUT"
 
   lint:
diff --git a/templates/python/.github/workflows/tests.yml b/templates/python/.github/workflows/tests.yml
index 781392d..93a8de2 100644
--- a/templates/python/.github/workflows/tests.yml
+++ b/templates/python/.github/workflows/tests.yml
@@ -1,6 +1,6 @@
 name: Python tests
 
-# Checks run in every docker compose service labelled dk.itkdev.python=true.
+# Checks run in every docker compose service labeled dk.itkdev.language=python.
 # The repository variable PYTHON_SERVICES (JSON list, e.g. ["api", "worker"])
 # overrides this.
 
@@ -34,8 +34,8 @@ jobs:
       - id: find
         run: |
           list=$(docker compose config --format json \
-            | jq -c '[.services | to_entries[] | select(.value.labels["dk.itkdev.python"] == "true") | .key]')
-          [ "$list" != "[]" ] || { echo "::error::No service has the label dk.itkdev.python=true"; exit 1; }
+            | jq -c '[.services | to_entries[] | select(.value.labels["dk.itkdev.language"] == "python") | .key]')
+          [ "$list" != "[]" ] || { echo "::error::No service has the label dk.itkdev.language=python"; exit 1; }
           echo "list=$list" >> "$GITHUB_OUTPUT"
 
   lock:
diff --git a/templates/python/docker-compose.yml b/templates/python/docker-compose.yml
index d655540..25f40ce 100644
--- a/templates/python/docker-compose.yml
+++ b/templates/python/docker-compose.yml
@@ -12,7 +12,7 @@ services:
       target: ${ENV:-dev}
     labels:
       # Picked up by the lint and tests workflows.
-      dk.itkdev.python: "true"
+      dk.itkdev.language: python
     ports:
       - "8000"
     healthcheck: