diff --git a/tests/unit/test_document_chunker.py b/tests/unit/test_document_chunker.py
index 9927c1c2..5ee184b2 100644
--- a/tests/unit/test_document_chunker.py
+++ b/tests/unit/test_document_chunker.py
@@ -1,11 +1,15 @@
 """Unit tests for DocumentChunker with LangChain text splitters."""
 
+import pytest
+
 from nextcloud_mcp_server.vector.document_chunker import (
     ChunkWithPosition,
     DocumentChunker,
     PageAwareChunker,
 )
 
+pytestmark = pytest.mark.unit
+
 
 def _make_doc(pages: list[str]) -> tuple[str, list[dict]]:
     """Build (full_text, page_boundaries) the way the PDF extractors do.