diff --git a/semantica/ingest/feed_ingestor.py b/semantica/ingest/feed_ingestor.py
index db68861a..0dc40559 100644
--- a/semantica/ingest/feed_ingestor.py
+++ b/semantica/ingest/feed_ingestor.py
@@ -359,9 +359,14 @@ class FeedParser:
 
             return parser.parse(date_string)
         except (ImportError, OSError):
+            # If dateutil isn't available, fall through to raising ValueError
             pass
+        except Exception as e:
+            # If dateutil fails to parse, raise ValueError to signal invalid input
+            raise ValueError(f"Invalid date format: {date_string}") from e
 
-        return None
+        # No known formats matched and dateutil is unavailable; raise ValueError
+        raise ValueError(f"Invalid date format: {date_string}")
 
     def validate_feed(self, feed_data: FeedData) -> bool:
         """
diff --git a/tests/ingest/test_file_ingestor.py b/tests/ingest/test_file_ingestor.py
index 60a18ac6..dc58c4d6 100644
--- a/tests/ingest/test_file_ingestor.py
+++ b/tests/ingest/test_file_ingestor.py
@@ -7,6 +7,7 @@ from unittest.mock import MagicMock
 # and we must populate the attributes that the code tries to import/patch.
 
 module_names = [
+    "boto3",
     "google",
     "google.cloud",
     "google.cloud.storage",
@@ -23,6 +24,7 @@ for name in module_names:
 # Explicitly add the classes that will be patched/used
 sys.modules["google.cloud.storage"].Client = MagicMock()
 sys.modules["azure.storage.blob"].BlobServiceClient = MagicMock()
+sys.modules["boto3"].client = MagicMock()
 
 from pathlib import Path  # noqa: E402
 from unittest.mock import patch  # noqa: E402