diff --git a/.github/workflows/build-and-publish.yml b/.github/workflows/build-and-publish.yml
index 3067968b0..e16c84b05 100644
--- a/.github/workflows/build-and-publish.yml
+++ b/.github/workflows/build-and-publish.yml
@@ -4,7 +4,7 @@ on:
   workflow_call:
     secrets:
       PYPI_TOKEN:
-          required: true
+        required: true
 
 jobs:
 
@@ -35,7 +35,7 @@ jobs:
       - name: GitHub Release
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        run: >
+        run: >-
           gh release create ${GITHUB_REF_NAME}
           --title ${GITHUB_REF_NAME}
           --notes-file ./doc/changes/changes_${GITHUB_REF_NAME}.md
diff --git a/.github/workflows/cd.yml b/.github/workflows/cd.yml
index 1fb0e2e00..98a11f62a 100644
--- a/.github/workflows/cd.yml
+++ b/.github/workflows/cd.yml
@@ -15,7 +15,8 @@ jobs:
       contents: read
 
   cd-job:
-    needs: [ check-tag-version-job ]
+    needs:
+      - check-tag-version-job
     name: Continuous Delivery
     uses: ./.github/workflows/build-and-publish.yml
     permissions:
@@ -24,7 +25,8 @@ jobs:
       PYPI_TOKEN: ${{ secrets.PYPI_TOKEN }}
 
   publish-docs:
-    needs: [ cd-job ]
+    needs:
+      - cd-job
     name: Publish Documentation
     uses: ./.github/workflows/gh-pages.yml
     permissions:
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d7f0a0f3f..5cba3e817 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -2,7 +2,7 @@ name: CI
 
 on:
   pull_request:
-      types: [opened, synchronize, reopened]
+    types: [opened, synchronize, reopened]
   schedule:
     # At 00:00 on every 7th day-of-month from 1 through 31. (https://crontab.guru)
     - cron: "0 0 1/7 * *"
@@ -16,7 +16,8 @@ jobs:
       contents: read
 
   Metrics:
-    needs: [ CI ]
+    needs:
+      - CI
     uses: ./.github/workflows/report.yml
     secrets: inherit
     permissions:
diff --git a/.github/workflows/gh-pages.yml b/.github/workflows/gh-pages.yml
index d47ce1f18..330218150 100644
--- a/.github/workflows/gh-pages.yml
+++ b/.github/workflows/gh-pages.yml
@@ -33,7 +33,8 @@ jobs:
           path: html-documentation
 
   deploy-documentation:
-    needs: [ build-documentation ]
+    needs:
+      - build-documentation
     permissions:
       contents: read
       pages: write
diff --git a/.github/workflows/merge-gate.yml b/.github/workflows/merge-gate.yml
index dc57b3599..74b3d93f9 100644
--- a/.github/workflows/merge-gate.yml
+++ b/.github/workflows/merge-gate.yml
@@ -27,7 +27,8 @@ jobs:
 
   slow-checks:
     name: Slow
-    needs: [ run-slow-tests ]
+    needs:
+      - run-slow-tests
     uses: ./.github/workflows/slow-checks.yml
     secrets: inherit
     permissions:
@@ -40,10 +41,11 @@ jobs:
     permissions:
       contents: read
     # If you need additional jobs to be part of the merge gate, add them below
-    needs: [ fast-checks, slow-checks ]
+    needs:
+      - fast-checks
+      - slow-checks
 
     # Each job requires a step, so we added this dummy step.
     steps:
       - name: Approve
-        run: |
-          echo "Merge Approved"
+        run: echo "Merge Approved"
diff --git a/.github/workflows/pr-merge.yml b/.github/workflows/pr-merge.yml
index a95cee5c3..544c8a94e 100644
--- a/.github/workflows/pr-merge.yml
+++ b/.github/workflows/pr-merge.yml
@@ -26,7 +26,8 @@ jobs:
       id-token: write
 
   metrics:
-    needs: [ ci-job ]
+    needs:
+      - ci-job
     uses: ./.github/workflows/report.yml
     secrets: inherit
     permissions:
diff --git a/.github/workflows/report.yml b/.github/workflows/report.yml
index 7a4a4857a..39502c9db 100644
--- a/.github/workflows/report.yml
+++ b/.github/workflows/report.yml
@@ -50,7 +50,7 @@ jobs:
           path: metrics.json
 
       - name: Generate GitHub Summary
-        run: |
+        run: |-
           echo -e "# Summary\n" >> $GITHUB_STEP_SUMMARY
           poetry run -- nox -s project:report -- --format markdown >> $GITHUB_STEP_SUMMARY
           poetry run -- nox -s dependency:licenses >> $GITHUB_STEP_SUMMARY
diff --git a/.github/workflows/slow-checks.yml b/.github/workflows/slow-checks.yml
index ae3aa4e9d..4707eaf26 100644
--- a/.github/workflows/slow-checks.yml
+++ b/.github/workflows/slow-checks.yml
@@ -12,7 +12,8 @@ jobs:
 
   tests:
     name: Integration-Tests (Python-${{ matrix.python-version }}, Exasol-${{ matrix.exasol-version}})
-    needs: [ build-matrix ]
+    needs:
+      - build-matrix
     runs-on: "ubuntu-24.04"
     permissions:
       contents: read
@@ -44,7 +45,8 @@ jobs:
 
 
   verify-poetry-installation:
-    needs: [ build-matrix ]
+    needs:
+     - build-matrix
     # This Job verifies if pipx installation is successful on each of the
     # selected GitHub Runners.
     strategy:
diff --git a/doc/changes/unreleased.md b/doc/changes/unreleased.md
index ab9f1d8c0..ea8fce542 100644
--- a/doc/changes/unreleased.md
+++ b/doc/changes/unreleased.md
@@ -5,3 +5,7 @@
 ## Documentation
 
 * #585: Added instructions how to ignore sonar issues to the User Guide
+
+## Refactoring
+
+* #686: Switched GitHub templates to be fully parsed by ruamel-yaml
diff --git a/exasol/toolbox/templates/github/workflows/build-and-publish.yml b/exasol/toolbox/templates/github/workflows/build-and-publish.yml
index cdf7ac950..74e4e5e21 100644
--- a/exasol/toolbox/templates/github/workflows/build-and-publish.yml
+++ b/exasol/toolbox/templates/github/workflows/build-and-publish.yml
@@ -4,7 +4,7 @@ on:
   workflow_call:
     secrets:
       PYPI_TOKEN:
-          required: true
+        required: true
 
 jobs:
 
diff --git a/exasol/toolbox/templates/github/workflows/cd.yml b/exasol/toolbox/templates/github/workflows/cd.yml
index 1fb0e2e00..99e2201f4 100644
--- a/exasol/toolbox/templates/github/workflows/cd.yml
+++ b/exasol/toolbox/templates/github/workflows/cd.yml
@@ -15,7 +15,8 @@ jobs:
       contents: read
 
   cd-job:
-    needs: [ check-tag-version-job ]
+    needs:
+     - check-tag-version-job
     name: Continuous Delivery
     uses: ./.github/workflows/build-and-publish.yml
     permissions:
@@ -24,7 +25,8 @@ jobs:
       PYPI_TOKEN: ${{ secrets.PYPI_TOKEN }}
 
   publish-docs:
-    needs: [ cd-job ]
+    needs:
+     - cd-job
     name: Publish Documentation
     uses: ./.github/workflows/gh-pages.yml
     permissions:
diff --git a/exasol/toolbox/templates/github/workflows/ci.yml b/exasol/toolbox/templates/github/workflows/ci.yml
index d7f0a0f3f..2cdd4db79 100644
--- a/exasol/toolbox/templates/github/workflows/ci.yml
+++ b/exasol/toolbox/templates/github/workflows/ci.yml
@@ -2,7 +2,7 @@ name: CI
 
 on:
   pull_request:
-      types: [opened, synchronize, reopened]
+    types: [opened, synchronize, reopened]
   schedule:
     # At 00:00 on every 7th day-of-month from 1 through 31. (https://crontab.guru)
     - cron: "0 0 1/7 * *"
@@ -16,7 +16,8 @@ jobs:
       contents: read
 
   Metrics:
-    needs: [ CI ]
+    needs:
+     - CI
     uses: ./.github/workflows/report.yml
     secrets: inherit
     permissions:
diff --git a/exasol/toolbox/templates/github/workflows/gh-pages.yml b/exasol/toolbox/templates/github/workflows/gh-pages.yml
index 71a3bdff3..87f57ad54 100644
--- a/exasol/toolbox/templates/github/workflows/gh-pages.yml
+++ b/exasol/toolbox/templates/github/workflows/gh-pages.yml
@@ -33,7 +33,8 @@ jobs:
           path: html-documentation
 
   deploy-documentation:
-    needs: [ build-documentation ]
+    needs:
+     - build-documentation
     permissions:
       contents: read
       pages: write
diff --git a/exasol/toolbox/templates/github/workflows/merge-gate.yml b/exasol/toolbox/templates/github/workflows/merge-gate.yml
index e1c2174a3..516110dc7 100644
--- a/exasol/toolbox/templates/github/workflows/merge-gate.yml
+++ b/exasol/toolbox/templates/github/workflows/merge-gate.yml
@@ -27,7 +27,8 @@ jobs:
 
   slow-checks:
     name: Slow
-    needs: [ run-slow-tests ]
+    needs:
+     - run-slow-tests
     uses: ./.github/workflows/slow-checks.yml
     secrets: inherit
     permissions:
@@ -40,10 +41,11 @@ jobs:
     permissions:
       contents: read
     # If you need additional jobs to be part of the merge gate, add them below
-    needs: [ fast-checks, slow-checks ]
+    needs:
+     - fast-checks
+     - slow-checks
 
     # Each job requires a step, so we added this dummy step.
     steps:
       - name: Approve
-        run: |
-          echo "Merge Approved"
+        run: echo "Merge Approved"
diff --git a/exasol/toolbox/templates/github/workflows/pr-merge.yml b/exasol/toolbox/templates/github/workflows/pr-merge.yml
index a95cee5c3..8cf903f02 100644
--- a/exasol/toolbox/templates/github/workflows/pr-merge.yml
+++ b/exasol/toolbox/templates/github/workflows/pr-merge.yml
@@ -26,7 +26,8 @@ jobs:
       id-token: write
 
   metrics:
-    needs: [ ci-job ]
+    needs:
+     - ci-job
     uses: ./.github/workflows/report.yml
     secrets: inherit
     permissions:
diff --git a/exasol/toolbox/templates/github/workflows/slow-checks.yml b/exasol/toolbox/templates/github/workflows/slow-checks.yml
index da1974bfc..c58d358f1 100644
--- a/exasol/toolbox/templates/github/workflows/slow-checks.yml
+++ b/exasol/toolbox/templates/github/workflows/slow-checks.yml
@@ -12,7 +12,8 @@ jobs:
 
   tests:
     name: Integration-Tests (Python-${{ matrix.python-version }}, Exasol-${{ matrix.exasol-version}})
-    needs: [ build-matrix ]
+    needs:
+      - build-matrix
     runs-on: "(( os_version ))"
     permissions:
       contents: read
diff --git a/exasol/toolbox/tools/template.py b/exasol/toolbox/tools/template.py
index 14829ea1f..1fcc28568 100644
--- a/exasol/toolbox/tools/template.py
+++ b/exasol/toolbox/tools/template.py
@@ -2,7 +2,6 @@
 import io
 from collections.abc import Mapping
 from contextlib import ExitStack
-from inspect import cleandoc
 from pathlib import Path
 from typing import (
     Any,
@@ -10,12 +9,11 @@
 
 import importlib_resources as resources
 import typer
-import yaml
-from jinja2 import Environment
 from rich.columns import Columns
 from rich.console import Console
 from rich.syntax import Syntax
 
+from exasol.toolbox.util.workflows.workflow import Workflow
 from noxconfig import PROJECT_CONFIG
 
 stdout = Console()
@@ -23,10 +21,6 @@
 
 CLI = typer.Typer()
 
-jinja_env = Environment(
-    variable_start_string="((", variable_end_string="))", autoescape=True
-)
-
 
 def _templates(pkg: str) -> Mapping[str, Any]:
     def _normalize(name: str) -> str:
@@ -72,18 +66,13 @@ def show_templates(
 
 def _render_template(
     src: str | Path,
-    stack: ExitStack,
 ) -> str:
-    input_file = stack.enter_context(open(src, encoding="utf-8"))
-
-    # dynamically render the template with Jinja2
-    template = jinja_env.from_string(input_file.read())
-    rendered_string = template.render(PROJECT_CONFIG.github_template_dict)
-
-    # validate that the rendered content is a valid YAML. This is not
-    # written out as by default it does not give GitHub-safe output.
-    yaml.safe_load(rendered_string)
-    return cleandoc(rendered_string) + "\n"
+    src_path = Path(src)
+    github_template_dict = PROJECT_CONFIG.github_template_dict
+    workflow = Workflow.load_from_template(
+        file_path=src_path, github_template_dict=github_template_dict
+    )
+    return workflow.content + "\n"
 
 
 def diff_template(template: str, dest: Path, pkg: str, template_type: str) -> None:
@@ -107,7 +96,7 @@ def diff_template(template: str, dest: Path, pkg: str, template_type: str) -> No
                     old = old.read().split("\n")
                     new = new.read().split("\n")
                 elif template_type == "workflow":
-                    new = _render_template(src=new, stack=stack)
+                    new = _render_template(src=new)
                     old = old.read().split("\n")
                     new = new.split("\n")
 
@@ -134,7 +123,7 @@ def _install_template(
             return
 
         output_file = stack.enter_context(open(dest, "wb"))
-        rendered_string = _render_template(src=src, stack=stack)
+        rendered_string = _render_template(src=src)
         output_file.write(rendered_string.encode("utf-8"))
 
 
diff --git a/exasol/toolbox/util/workflows/__init__.py b/exasol/toolbox/util/workflows/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/exasol/toolbox/util/workflows/template_processing.py b/exasol/toolbox/util/workflows/template_processing.py
new file mode 100644
index 000000000..e78deba45
--- /dev/null
+++ b/exasol/toolbox/util/workflows/template_processing.py
@@ -0,0 +1,44 @@
+from dataclasses import dataclass
+from typing import Any
+
+from jinja2 import Environment
+
+jinja_env = Environment(
+    variable_start_string="((", variable_end_string="))", autoescape=True
+)
+
+import io
+from inspect import cleandoc
+
+from ruamel.yaml import YAML
+
+
+@dataclass(frozen=True)
+class TemplateRenderer:
+    template_str: str
+    github_template_dict: dict[str, Any]
+
+    def _render_with_jinja(self, input_str: str) -> str:
+        """
+        Render the template with Jinja.
+        """
+        jinja_template = jinja_env.from_string(input_str)
+        return jinja_template.render(self.github_template_dict)
+
+    def render_to_workflow(self) -> str:
+        """
+        Render the template to the contents of a valid GitHub workflow.
+        """
+        yaml = YAML()
+        yaml.width = 200
+        yaml.preserve_quotes = True
+        yaml.sort_base_mapping_type_on_output = False  # type: ignore
+        yaml.indent(mapping=2, sequence=4, offset=2)
+
+        workflow_string = self._render_with_jinja(self.template_str)
+        workflow_dict = yaml.load(workflow_string)
+
+        stream = io.StringIO()
+        yaml.dump(workflow_dict, stream)
+        workflow_string = stream.getvalue()
+        return cleandoc(workflow_string)
diff --git a/exasol/toolbox/util/workflows/workflow.py b/exasol/toolbox/util/workflows/workflow.py
new file mode 100644
index 000000000..83964a2ea
--- /dev/null
+++ b/exasol/toolbox/util/workflows/workflow.py
@@ -0,0 +1,30 @@
+from pathlib import Path
+from typing import Any
+
+from pydantic import (
+    BaseModel,
+    ConfigDict,
+)
+
+from exasol.toolbox.util.workflows.template_processing import TemplateRenderer
+
+
+class Workflow(BaseModel):
+    model_config = ConfigDict(frozen=True, arbitrary_types_allowed=True)
+
+    content: str
+
+    @classmethod
+    def load_from_template(cls, file_path: Path, github_template_dict: dict[str, Any]):
+        if not file_path.exists():
+            raise FileNotFoundError(file_path)
+
+        try:
+            raw_content = file_path.read_text()
+            template_renderer = TemplateRenderer(
+                template_str=raw_content, github_template_dict=github_template_dict
+            )
+            workflow = template_renderer.render_to_workflow()
+            return cls(content=workflow)
+        except Exception as e:
+            raise ValueError(f"Error rendering file: {file_path}") from e
diff --git a/poetry.lock b/poetry.lock
index 94fb0f9bd..9db334592 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -2165,14 +2165,14 @@ tests = ["pytest (>=9)", "typing-extensions (>=4.15)"]
 
 [[package]]
 name = "pip"
-version = "25.3"
+version = "26.0"
 description = "The PyPA recommended tool for installing Python packages."
 optional = false
 python-versions = ">=3.9"
 groups = ["main"]
 files = [
-    {file = "pip-25.3-py3-none-any.whl", hash = "sha256:9655943313a94722b7774661c21049070f6bbb0a1516bf02f7c8d5d9201514cd"},
-    {file = "pip-25.3.tar.gz", hash = "sha256:8d0538dbbd7babbd207f261ed969c65de439f6bc9e5dbd3b3b9a77f25d95f343"},
+    {file = "pip-26.0-py3-none-any.whl", hash = "sha256:98436feffb9e31bc9339cf369fd55d3331b1580b6a6f1173bacacddcf9c34754"},
+    {file = "pip-26.0.tar.gz", hash = "sha256:3ce220a0a17915972fbf1ab451baae1521c4539e778b28127efa79b974aff0fa"},
 ]
 
 [[package]]
@@ -3943,4 +3943,4 @@ type = ["pytest-mypy"]
 [metadata]
 lock-version = "2.1"
 python-versions = ">=3.10,<4.0"
-content-hash = "8a5d05c9cc28f8599edd5055881b350ebf0588dcaed75656aa1ad2cc30b4d7ce"
+content-hash = "d1f9d88ca70834f069d89f24b82e2109852867a1a58396250c9c4ad89119f9af"
diff --git a/pyproject.toml b/pyproject.toml
index 65d080cc3..edf00a9ee 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -47,7 +47,7 @@ dependencies = [
     "pysonar>=1.0.1.1548,<2",
     "pytest>=7.2.2,<10",
     "pyupgrade>=2.38.2,<4.0.0",
-    "pyyaml (>=6.0.3,<7.0.0)",
+    "ruamel-yaml (>=0.18.0,<=0.18.16)",
     "ruff>=0.14.5,<0.15",
     "shibuya>=2024.5.14",
     "sphinx>=5.3,<8",
diff --git a/test/integration/tools/workflow_test.py b/test/integration/tools/workflow_integration_test.py
similarity index 100%
rename from test/integration/tools/workflow_test.py
rename to test/integration/tools/workflow_integration_test.py
diff --git a/test/unit/template_test.py b/test/unit/tool_template_test.py
similarity index 100%
rename from test/unit/template_test.py
rename to test/unit/tool_template_test.py
diff --git a/test/unit/tools/test_template.py b/test/unit/tools/test_template.py
deleted file mode 100644
index 354695805..000000000
--- a/test/unit/tools/test_template.py
+++ /dev/null
@@ -1,149 +0,0 @@
-from contextlib import ExitStack
-from inspect import cleandoc
-
-import pytest
-from yaml.parser import ParserError
-
-from exasol.toolbox.tools.template import (
-    _render_template,
-)
-
-TEMPLATE = """
-name: Publish Documentation
-
-on:
-  workflow_call:
-  workflow_dispatch:
-
-jobs:
-
-  build-documentation:
-    runs-on: "(( os_version ))"
-    permissions:
-      contents: read
-    steps:
-      - name: SCM Checkout
-        uses: actions/checkout@v6
-        with:
-          fetch-depth: 0
-
-      - name: Setup Python & Poetry Environment
-        uses: exasol/python-toolbox/.github/actions/python-environment@v5
-        with:
-          python-version: "(( minimum_python_version ))"
-          poetry-version: "(( dependency_manager_version ))"
-
-      - name: Build Documentation
-        run: |
-          poetry run -- nox -s docs:multiversion
-          mv .html-documentation html-documentation
-
-      - name: Upload artifact
-        uses: actions/upload-pages-artifact@v4
-        with:
-          path: html-documentation
-
-  deploy-documentation:
-    needs: [ build-documentation ]
-    permissions:
-      contents: read
-      pages: write
-      id-token: write
-    environment:
-      name: github-pages
-      url: ${{ steps.deployment.outputs.page_url }}
-    runs-on: "(( os_version ))"
-    steps:
-      - name: Deploy to GitHub Pages
-        id: deployment
-        uses: actions/deploy-pages@v4
-
-"""
-
-RENDERED_TEMPLATE = """
-name: Publish Documentation
-
-on:
-  workflow_call:
-  workflow_dispatch:
-
-jobs:
-
-  build-documentation:
-    runs-on: "ubuntu-24.04"
-    permissions:
-      contents: read
-    steps:
-      - name: SCM Checkout
-        uses: actions/checkout@v6
-        with:
-          fetch-depth: 0
-
-      - name: Setup Python & Poetry Environment
-        uses: exasol/python-toolbox/.github/actions/python-environment@v5
-        with:
-          python-version: "3.10"
-          poetry-version: "2.3.0"
-
-      - name: Build Documentation
-        run: |
-          poetry run -- nox -s docs:multiversion
-          mv .html-documentation html-documentation
-
-      - name: Upload artifact
-        uses: actions/upload-pages-artifact@v4
-        with:
-          path: html-documentation
-
-  deploy-documentation:
-    needs: [ build-documentation ]
-    permissions:
-      contents: read
-      pages: write
-      id-token: write
-    environment:
-      name: github-pages
-      url: ${{ steps.deployment.outputs.page_url }}
-    runs-on: "ubuntu-24.04"
-    steps:
-      - name: Deploy to GitHub Pages
-        id: deployment
-        uses: actions/deploy-pages@v4
-
-"""
-
-BAD_TEMPLATE = """
-name: Publish Documentation
-
-on:
-  workflow_call:
-  workflow_dispatch:
-
-jobs:
-
-  build-documentation:
-    runs-on: "ubuntu-24.04"
-    permissions:
-      contents: read
-    steps:
-      - name: SCM Checkout
-      uses: actions/checkout@v5
-"""
-
-
-class TestRenderTemplate:
-    @staticmethod
-    def test_works_as_expected(tmp_path):
-        file_path = tmp_path / "test.yml"
-        file_path.write_text(TEMPLATE)
-        with ExitStack() as stack:
-            rendered_str = _render_template(src=file_path, stack=stack)
-        assert rendered_str == cleandoc(RENDERED_TEMPLATE) + "\n"
-
-    @staticmethod
-    def test_fails_when_yaml_malformed(tmp_path):
-        file_path = tmp_path / "test.yaml"
-        file_path.write_text(BAD_TEMPLATE)
-        with pytest.raises(ParserError, match="while parsing a block collection"):
-            with ExitStack() as stack:
-                _render_template(src=file_path, stack=stack)
diff --git a/test/unit/util/workflows/template_processing_test.py b/test/unit/util/workflows/template_processing_test.py
new file mode 100644
index 000000000..93b6b2dfe
--- /dev/null
+++ b/test/unit/util/workflows/template_processing_test.py
@@ -0,0 +1,178 @@
+from inspect import cleandoc
+
+from exasol.toolbox.util.workflows.template_processing import TemplateRenderer
+from noxconfig import PROJECT_CONFIG
+
+
+class TestTemplateRenderer:
+    @staticmethod
+    def test_works_for_general_case():
+        input_yaml = """
+        name: Build & Publish
+
+        on:
+          workflow_call:
+            secrets:
+              PYPI_TOKEN:
+                required: true
+
+        jobs:
+          cd-job:
+            name: Continuous Delivery
+            permissions:
+              contents: write
+        """
+
+        template_renderer = TemplateRenderer(
+            template_str=cleandoc(input_yaml),
+            github_template_dict=PROJECT_CONFIG.github_template_dict,
+        )
+        assert template_renderer.render_to_workflow() == cleandoc(input_yaml)
+
+    @staticmethod
+    def test_fixes_extra_horizontal_whitespace():
+        # required has 2 extra spaces
+        input_yaml = """
+        name: Build & Publish
+
+        on:
+          workflow_call:
+            secrets:
+              PYPI_TOKEN:
+                  required: true
+        """
+
+        expected_yaml = """
+        name: Build & Publish
+
+        on:
+          workflow_call:
+            secrets:
+              PYPI_TOKEN:
+                required: true
+        """
+
+        template_renderer = TemplateRenderer(
+            template_str=cleandoc(input_yaml),
+            github_template_dict=PROJECT_CONFIG.github_template_dict,
+        )
+        assert template_renderer.render_to_workflow() == cleandoc(expected_yaml)
+
+    @staticmethod
+    def test_keeps_comments():
+        input_yaml = """
+        steps:
+          # Comment in nested area
+          - name: SCM Checkout # Comment inline
+            uses: actions/checkout@v6
+            # Comment in step
+        """
+
+        expected_yaml = """
+        steps:
+        # Comment in nested area
+        - name: SCM Checkout # Comment inline
+          uses: actions/checkout@v6
+          # Comment in step
+        """
+
+        template_renderer = TemplateRenderer(
+            template_str=cleandoc(input_yaml),
+            github_template_dict=PROJECT_CONFIG.github_template_dict,
+        )
+
+        assert template_renderer.render_to_workflow() == cleandoc(expected_yaml)
+
+    @staticmethod
+    def test_keeps_quotes_for_variables_as_is():
+        input_yaml = """
+        - name: Build Artifacts
+          run: poetry build
+        - name: PyPi Release
+          env:
+            POETRY_HTTP_BASIC_PYPI_USERNAME: "__token__"
+            POETRY_HTTP_BASIC_PYPI_PASSWORD: "${{ secrets.PYPI_TOKEN }}"
+          run: poetry publish
+        - name: GitHub Release
+          env:
+            GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          run: >
+            gh release create ${GITHUB_REF_NAME}
+            --title ${GITHUB_REF_NAME}
+            --notes-file ./doc/changes/changes_${GITHUB_REF_NAME}.md
+            dist/*
+        """
+
+        expected_yaml = """
+        - name: Build Artifacts
+          run: poetry build
+        - name: PyPi Release
+          env:
+            POETRY_HTTP_BASIC_PYPI_USERNAME: "__token__"
+            POETRY_HTTP_BASIC_PYPI_PASSWORD: "${{ secrets.PYPI_TOKEN }}"
+          run: poetry publish
+        - name: GitHub Release
+          env:
+            GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          run: >-
+            gh release create ${GITHUB_REF_NAME}
+            --title ${GITHUB_REF_NAME}
+            --notes-file ./doc/changes/changes_${GITHUB_REF_NAME}.md
+            dist/*
+        """
+
+        template_renderer = TemplateRenderer(
+            template_str=cleandoc(input_yaml),
+            github_template_dict=PROJECT_CONFIG.github_template_dict,
+        )
+
+        assert template_renderer.render_to_workflow() == cleandoc(expected_yaml)
+
+    @staticmethod
+    def test_updates_jinja_variables():
+        input_yaml = """
+        - name: Setup Python & Poetry Environment
+          uses: exasol/python-toolbox/.github/actions/python-environment@v5
+          with:
+            python-version: "(( minimum_python_version ))"
+            poetry-version: "(( dependency_manager_version ))"
+        """
+        expected_yaml = """
+        - name: Setup Python & Poetry Environment
+        uses: exasol/python-toolbox/.github/actions/python-environment@v5
+        with:
+          python-version: "3.10"
+          poetry-version: "2.3.0"
+        """
+
+        template_renderer = TemplateRenderer(
+            template_str=cleandoc(input_yaml),
+            github_template_dict=PROJECT_CONFIG.github_template_dict,
+        )
+
+        assert template_renderer.render_to_workflow() == cleandoc(expected_yaml)
+
+    @staticmethod
+    def test_preserves_list_format():
+        input_yaml = """
+        on:
+          pull_request:
+            types: [opened, synchronize, reopened]
+
+        Type-Check:
+          name: Type Checking (Python-${{ matrix.python-versions }})
+          runs-on: "ubuntu-24.04"
+          permissions:
+            contents: read
+          strategy:
+            fail-fast: false
+            matrix:
+              python-versions: ["3.10", "3.11", "3.12", "3.13", "3.14"]
+        """
+
+        template_renderer = TemplateRenderer(
+            template_str=cleandoc(input_yaml),
+            github_template_dict=PROJECT_CONFIG.github_template_dict,
+        )
+
+        assert template_renderer.render_to_workflow() == cleandoc(input_yaml)
diff --git a/test/unit/util/workflows/workflow_test.py b/test/unit/util/workflows/workflow_test.py
new file mode 100644
index 000000000..dafb0665e
--- /dev/null
+++ b/test/unit/util/workflows/workflow_test.py
@@ -0,0 +1,58 @@
+import pytest
+from ruamel.yaml.parser import ParserError
+
+from exasol.toolbox.util.workflows.workflow import Workflow
+from noxconfig import PROJECT_CONFIG
+
+BAD_TEMPLATE = """
+name: Publish Documentation
+
+on:
+  workflow_call:
+  workflow_dispatch:
+
+jobs:
+
+  build-documentation:
+    runs-on: "ubuntu-24.04"
+    permissions:
+      contents: read
+    steps:
+      - name: SCM Checkout
+      uses: actions/checkout@v5
+"""
+
+TEMPLATE_DIR = PROJECT_CONFIG.source_code_path / "templates" / "github" / "workflows"
+
+
+class TestWorkflow:
+    @staticmethod
+    @pytest.mark.parametrize("template_path", list(TEMPLATE_DIR.glob("*.yml")))
+    def test_works_for_all_templates(template_path):
+        Workflow.load_from_template(
+            file_path=template_path,
+            github_template_dict=PROJECT_CONFIG.github_template_dict,
+        )
+
+    @staticmethod
+    def test_fails_when_yaml_does_not_exist(tmp_path):
+        file_path = tmp_path / "test.yaml"
+        with pytest.raises(FileNotFoundError, match="test.yaml"):
+            Workflow.load_from_template(
+                file_path=file_path,
+                github_template_dict=PROJECT_CONFIG.github_template_dict,
+            )
+
+    @staticmethod
+    def test_fails_when_yaml_malformed(tmp_path):
+        file_path = tmp_path / "test.yaml"
+        file_path.write_text(BAD_TEMPLATE)
+
+        with pytest.raises(ValueError, match="Error rendering file") as excinfo:
+            Workflow.load_from_template(
+                file_path=file_path,
+                github_template_dict=PROJECT_CONFIG.github_template_dict,
+            )
+
+        assert isinstance(excinfo.value.__cause__, ParserError)
+        assert "while parsing a block collection" in str(excinfo.value.__cause__)