diff --git a/test_amateurfunk_anki.py b/test_amateurfunk_anki.py
index 3fdf7ba..ad86a07 100644
--- a/test_amateurfunk_anki.py
+++ b/test_amateurfunk_anki.py
@@ -489,5 +489,29 @@ class TestAnkiBuild(unittest.TestCase):
             self.assertEqual(first.read_bytes(), second.read_bytes(), first.name)
 
 
+class TestRealExplanationsFile(unittest.TestCase):
+    """Validate the repo's actual explanations.json against the live catalog.
+
+    The other tests are hermetic by design: they exercise the schema
+    validator on synthetic fixtures so the validator's own logic is
+    tested without coupling to editorial data. That leaves a gap — a
+    real malformed entry or stale key in the repo's explanations.json
+    would not show up in `python3 -m unittest`. This test closes it
+    when the fetched catalog is present, and skips otherwise so an
+    unfetched checkout still runs the rest of the suite.
+    """
+
+    def test_repo_explanations_pass_schema_and_match_catalog(self):
+        repo = Path(__file__).resolve().parent
+        explanations_path = repo / "explanations.json"
+        catalogs = sorted((repo / "data").glob("*/fragenkatalog*.json"))
+        if not explanations_path.exists() or not catalogs:
+            self.skipTest("explanations.json or fetched catalog not available")
+        explanations = aa.load_explanations(explanations_path)
+        catalog = json.loads(catalogs[-1].read_text("utf-8"))
+        categories = aa.collect_categories(catalog)
+        aa._check_explanation_keys_against_catalog(explanations, categories)
+
+
 if __name__ == "__main__":
     unittest.main()