diff --git a/backend/open_webui/utils/middleware.py b/backend/open_webui/utils/middleware.py
index 18bddc531..5dd8ed3f5 100644
--- a/backend/open_webui/utils/middleware.py
+++ b/backend/open_webui/utils/middleware.py
@@ -2241,34 +2241,18 @@ async def process_chat_payload(request, form_data, user, metadata, model):
                         folder.data["system_prompt"], form_data, metadata, user
                     )
                 if "files" in folder.data:
-                    folder_files = folder.data["files"]
                     if (
                         metadata.get("params", {}).get("function_calling")
-                        == "native"
+                        != "native"
                     ):
-                        # Native FC: knowledge files will be handled by the
-                        # builtin query_knowledge_files tool, not RAG.
-                        knowledge_files = [
-                            f
-                            for f in folder_files
-                            if f.get("type") == "collection"
-                            or f.get("collection_names")
-                        ]
-                        attachment_files = [
-                            f
-                            for f in folder_files
-                            if f not in knowledge_files
-                        ]
                         form_data["files"] = [
-                            *attachment_files,
+                            *folder.data["files"],
                             *form_data.get("files", []),
                         ]
-                        metadata["folder_knowledge"] = knowledge_files
                     else:
-                        form_data["files"] = [
-                            *folder_files,
-                            *form_data.get("files", []),
-                        ]
+                        # Native FC: skip RAG injection, builtin tools
+                        # will read folder knowledge from metadata.
+                        metadata["folder_knowledge"] = folder.data["files"]
 
     # Model "Knowledge" handling
     user_message = get_last_user_message(form_data["messages"])