diff --git a/llama_stack/providers/registry/vector_io.py b/llama_stack/providers/registry/vector_io.py
index 0ba67411b..70148eb15 100644
--- a/llama_stack/providers/registry/vector_io.py
+++ b/llama_stack/providers/registry/vector_io.py
@@ -466,6 +466,7 @@ See [Weaviate's documentation](https://weaviate.io/developers/weaviate) for more
 """,
             ),
             api_dependencies=[Api.inference],
+            optional_api_dependencies=[Api.files],
         ),
         InlineProviderSpec(
             api=Api.vector_io,
diff --git a/llama_stack/providers/remote/vector_io/milvus/milvus.py b/llama_stack/providers/remote/vector_io/milvus/milvus.py
index e681e5a99..0eaae81b3 100644
--- a/llama_stack/providers/remote/vector_io/milvus/milvus.py
+++ b/llama_stack/providers/remote/vector_io/milvus/milvus.py
@@ -290,10 +290,12 @@ class MilvusIndex(EmbeddingIndex):
 
     async def delete_chunks(self, chunks_for_deletion: list[ChunkForDeletion]) -> None:
         """Remove a chunk from the Milvus collection."""
-        chunk_ids_str = ",".join(f"'{c.chunk_id}'" for c in chunks_for_deletion)
+        chunk_ids = [c.chunk_id for c in chunks_for_deletion]
         try:
+            # Use IN clause with square brackets and single quotes for VARCHAR field
+            chunk_ids_str = ", ".join(f"'{chunk_id}'" for chunk_id in chunk_ids)
             await asyncio.to_thread(
-                self.client.delete, collection_name=self.collection_name, filter=f"chunk_id in ({chunk_ids_str})"
+                self.client.delete, collection_name=self.collection_name, filter=f"chunk_id in [{chunk_ids_str}]"
             )
         except Exception as e:
             logger.error(f"Error deleting chunks from Milvus collection {self.collection_name}: {e}")