diff --git a/lightrag_webui/src/features/RetrievalTesting.tsx b/lightrag_webui/src/features/RetrievalTesting.tsx
index c9781a41..20440332 100644
--- a/lightrag_webui/src/features/RetrievalTesting.tsx
+++ b/lightrag_webui/src/features/RetrievalTesting.tsx
@@ -261,10 +261,12 @@ export default function RetrievalTesting() {
       const queryParams = {
         ...state.querySettings,
         query: actualQuery,
-        conversation_history: prevMessages
-          .filter((m) => m.isError !== true)
-          .slice(-(state.querySettings.history_turns || 0) * 2)
-          .map((m) => ({ role: m.role, content: m.content })),
+        conversation_history: (state.querySettings.history_turns || 0) > 0
+          ? prevMessages
+            .filter((m) => m.isError !== true)
+            .slice(-(state.querySettings.history_turns || 0) * 2)
+            .map((m) => ({ role: m.role, content: m.content }))
+          : [],
         ...(modeOverride ? { mode: modeOverride } : {})
       }