diff --git a/.github/workflows/coverage.yml b/.github/workflows/coverage.yml
index 98fe259..e138c8f 100644
--- a/.github/workflows/coverage.yml
+++ b/.github/workflows/coverage.yml
@@ -13,6 +13,8 @@ jobs:
         os: [ubuntu-latest]
     steps:
       - uses: actions/checkout@v4
+        with:
+          submodules: 'recursive'
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v5
         with:
diff --git a/.github/workflows/unittests.yml b/.github/workflows/unittests.yml
index 3cf5358..ec1ce60 100644
--- a/.github/workflows/unittests.yml
+++ b/.github/workflows/unittests.yml
@@ -13,6 +13,8 @@ jobs:
         os: [ubuntu-latest]
     steps:
       - uses: actions/checkout@v4
+        with:
+          submodules: 'recursive'
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v5
         with:
diff --git a/docker-compose.yaml b/docker-compose.yaml
index c6339fd..ec6319c 100644
--- a/docker-compose.yaml
+++ b/docker-compose.yaml
@@ -1,7 +1,9 @@
 services:
   kroki:
     image: yuzutech/kroki:0.24.1
-
+    ports:
+      - "8000:8000"  # Expose localhost:8000
+      # this is required for the test_main.py to directly use kroki
   scrape-and-plot:
     build: .
     image: ghcr.io/hochfrequenz/ebd_toolchain:latest
diff --git a/pyproject.toml b/pyproject.toml
index 5f0cf24..01bd931 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -18,7 +18,7 @@ classifiers = [
 ]
 dependencies = [
     "ebdamame>=0.1.3",
-    "rebdhuhn>=0.4.0",
+    "rebdhuhn>=0.5.1",
     "cattrs",
     "click",
     "pydantic-settings"
diff --git a/src/ebd_toolchain/main.py b/src/ebd_toolchain/main.py
index d4c4268..7979af4 100644
--- a/src/ebd_toolchain/main.py
+++ b/src/ebd_toolchain/main.py
@@ -36,7 +36,7 @@
 from pydantic_settings import BaseSettings, SettingsConfigDict
 from rebdhuhn.graph_conversion import convert_table_to_graph
 from rebdhuhn.graphviz import convert_dot_to_svg_kroki, convert_graph_to_dot
-from rebdhuhn.kroki import DotToSvgConverter, Kroki
+from rebdhuhn.kroki import DotToSvgConverter, Kroki, KrokiDotBadRequestError, KrokiPlantUmlBadRequestError
 from rebdhuhn.models.ebd_graph import EbdGraph
 from rebdhuhn.models.ebd_table import EbdTable
 from rebdhuhn.models.errors import (
@@ -108,11 +108,16 @@ def _dump_json(json_path: Path, ebd_table: EbdTable) -> None:
     multiple=True,
     help="Choose which file you'd like to create",
 )
-# pylint:disable=too-many-locals, too-many-branches, too-many-statements,
 def main(input_path: Path, output_path: Path, export_types: list[Literal["puml", "dot", "json", "svg"]]) -> None:
     """
     A program to get a machine-readable version of the AHBs docx files published by edi@energy.
     """
+    _main(input_path, output_path, export_types)
+
+
+# pylint:disable=too-many-locals, too-many-branches, too-many-statements,
+def _main(input_path: Path, output_path: Path, export_types: list[Literal["puml", "dot", "json", "svg"]]) -> None:
+    """same as main but without the click decorators"""
     settings = Settings()  # type:ignore[call-arg]
     # read settings from environment variable/.env file
     kroki_client = Kroki(kroki_host=f"http://{settings.kroki_host}:{settings.kroki_port}")
@@ -175,7 +180,11 @@ def handle_known_error(error: Exception, ebd_key: str) -> None:
             except AssertionError as assertion_error:
                 # https://github.com/Hochfrequenz/rebdhuhn/issues/35
                 click.secho(str(assertion_error), fg="red")
-            except (NotExactlyTwoOutgoingEdgesError, GraphTooComplexForPlantumlError) as known_issue:
+            except (
+                NotExactlyTwoOutgoingEdgesError,
+                GraphTooComplexForPlantumlError,
+                KrokiPlantUmlBadRequestError,
+            ) as known_issue:
                 handle_known_error(known_issue, ebd_key)
             except Exception as general_error:  # pylint:disable=broad-exception-caught
                 click.secho(f"Error while exporting {ebd_key} as UML: {str(general_error)}; Skip!", fg="yellow")
@@ -189,7 +198,7 @@ def handle_known_error(error: Exception, ebd_key: str) -> None:
                 svg_path = output_path / Path(f"{ebd_key}.svg")
                 _dump_svg(svg_path, ebd_graph, kroki_client)
                 click.secho(f"💾 Successfully exported '{ebd_key}.svg' to {svg_path.absolute()}")
-        except PathsNotGreaterThanOneError as known_issue:
+        except (PathsNotGreaterThanOneError, KrokiDotBadRequestError) as known_issue:
             handle_known_error(known_issue, ebd_key)
         except AssertionError as assertion_error:
             # e.g. AssertionError: If indegree > 1, the number of paths should always be greater than 1 too.
diff --git a/unittests/test_main.py b/unittests/test_main.py
new file mode 100644
index 0000000..e0d0988
--- /dev/null
+++ b/unittests/test_main.py
@@ -0,0 +1,39 @@
+"""
+tests the main script
+"""
+
+from pathlib import Path
+from typing import Literal
+
+import pytest
+from _pytest.monkeypatch import MonkeyPatch
+
+from ebd_toolchain.main import _main
+
+repo_root = Path(__file__).parent.parent
+recent_docx_file = (
+    repo_root
+    / "edi_energy_mirror"
+    / "edi_energy_de"
+    / "FV2504"
+    / "Entscheidungsbaum-DiagrammeundCodelisten-informatorischeLesefassung4.0a_99991231_20250404.docx"
+)
+assert recent_docx_file.exists()
+
+
+@pytest.mark.parametrize(
+    "input_path, export_types", [pytest.param(recent_docx_file, ["puml", "dot", "json", "svg"], id="recent call")]
+)
+def test_main(
+    input_path: Path,
+    export_types: list[Literal["puml", "dot", "json", "svg"]],
+    tmp_path: Path,
+    monkeypatch: MonkeyPatch,
+) -> None:
+    monkeypatch.setenv("KROKI_PORT", "8000")
+    monkeypatch.setenv("KROKI_HOST", "localhost")
+    # if you run into ConnectionErrors use
+    # docker-compose up -d
+    # in the repo root
+    _main(input_path, tmp_path, export_types)
+    # we don't assert on the results but instead just check that it doesn't crash