diff --git a/ai_ta_backend/beam/ingest.py b/ai_ta_backend/beam/ingest.py
index 5dfca7fd..a8ec7786 100644
--- a/ai_ta_backend/beam/ingest.py
+++ b/ai_ta_backend/beam/ingest.py
@@ -14,7 +14,7 @@
 import uuid
 from pathlib import Path
 from tempfile import NamedTemporaryFile
-from typing import Any, Callable, Dict, List, Union
+from typing import Any, Callable, Dict, List, Optional, Union
 
 import beam
 import boto3
@@ -245,7 +245,7 @@ def _ingest_single(ingest_method: Callable, s3_path, *args, **kwargs):
         with NamedTemporaryFile(suffix=file_extension) as tmpfile:
           self.s3_client.download_fileobj(Bucket=os.environ['S3_BUCKET_NAME'], Key=s3_path, Fileobj=tmpfile)
           mime_type = str(mimetypes.guess_type(tmpfile.name, strict=False)[0])
-          mime_category, mime_subcategory = mime_type.split('/')
+          mime_category = mime_type.split('/')[0] if '/' in mime_type else mime_type
 
         if file_extension in file_ingest_methods:
           # Use specialized functions when possible, fallback to mimetype. Else raise error.