From ceff4026029e58530365e6d14929ce8f26eb2d7b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9mentine=20Fourrier?=
 <22726840+clefourrier@users.noreply.github.com>
Date: Tue, 24 Jun 2025 14:04:59 +0200
Subject: [PATCH] Fix system prompt concatenated with instruction in chat
 template

---
 src/lighteval/tasks/prompt_manager.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/lighteval/tasks/prompt_manager.py b/src/lighteval/tasks/prompt_manager.py
index 3ec959cb9..22fc9d502 100644
--- a/src/lighteval/tasks/prompt_manager.py
+++ b/src/lighteval/tasks/prompt_manager.py
@@ -310,10 +310,10 @@ def get_examples(  # noqa: C901
 
         # System prompt and instruction
         if use_chat_template:
-            if system_prompt is not None:  # We add system prompt and instruction jointly if possible
-                examples.insert(0, {"role": "system", "content": system_prompt + instruction})
-            else:  # Else we add the instruction to the first example
-                examples[0]["content"] = instruction + examples[0]["content"]
+            # We add the instruction to the first example
+            examples[0]["content"] = instruction + examples[0]["content"]
+            if system_prompt is not None:  # We add system prompt if available
+                examples.insert(0, {"role": "system", "content": system_prompt})
             return examples
         else:
             system_prompt = system_prompt if system_prompt is not None else ""