diff --git a/src/caoscrawler/converters/converters.py b/src/caoscrawler/converters/converters.py
index da752f685ab3106f8dc8bc1226f1c7c3143ec4f1..df0d77b1184a7a9418ccd0be292a7b4c452a8e6b 100644
--- a/src/caoscrawler/converters/converters.py
+++ b/src/caoscrawler/converters/converters.py
@@ -831,13 +831,13 @@ class DirectoryConverter(Converter):
             stamp_str = ref_file.readline().strip()
             try:
                 return datetime.datetime.fromisoformat(stamp_str)
-            except ValueError:
-                logger.warn(
+            except ValueError as e:
+                logger.error(
                     f"Reference file in {self.definition['match_newer_than_file']} "
                     "doesn't contain a ISO formatted datetime in its first line. "
                     "Match regardless of modification times."
                 )
-                return datetime.datetime.min
+                raise e
 
 
 class SimpleFileConverter(Converter):
diff --git a/unittests/test_converters.py b/unittests/test_converters.py
index 7b22aa84646729caea171e14666ea1dd843b5ed6..e4b442d91060c7ba98cb1a910156b1800f050be3 100644
--- a/unittests/test_converters.py
+++ b/unittests/test_converters.py
@@ -1113,9 +1113,10 @@ def test_directory_converter_change_date(caplog, converter_registry):
     # Match but warn
     with open(tmpfi.name, "w") as fi:
         fi.write(f"This is garbage.\n")
-    assert dc.match(test_dir_element) is not None
+    with pytest.raises(ValueError):
+        dc.match(test_dir_element)
     assert len(caplog.record_tuples) == 1
-    assert caplog.record_tuples[0][1] == logging.WARNING
+    assert caplog.record_tuples[0][1] == logging.ERROR
     assert tmpfi.name in caplog.record_tuples[0][2]
     assert "doesn't contain a ISO formatted datetime in its first line" in caplog.record_tuples[0][2]