diff --git a/frontend/components/KnowledgeBase.tsx b/frontend/components/KnowledgeBase.tsx
index cbbcb29..b933388 100644
--- a/frontend/components/KnowledgeBase.tsx
+++ b/frontend/components/KnowledgeBase.tsx
@@ -184,6 +184,7 @@ export const KnowledgeBase: React.FC = () => {
 
     const handleRemoveDoc = async (docId: string) => {
         if (!selectedKb) return;
+        if (!confirm('Are you sure you want to delete this document? This action cannot be undone.')) return;
         try {
             await apiService.removeSourceDocument(selectedKb.id, docId);
             await loadKbDetail(selectedKb.id);