diff --git a/engine_llm.py b/engine_llm.py
index ecf47fd..6ed296c 100644
--- a/engine_llm.py
+++ b/engine_llm.py
@@ -51,6 +51,7 @@ def run_llm_processor(in_queue, out_queue, args):
                 json={
                     "model": args.post_correct_model,
                     "prompt": "Return exactly: ok",
+                    "system": "You are a concise assistant.",
                     "stream": False,
                     "options": {"temperature": 0.0},
                     "keep_alive": getattr(args, "post_correct_keep_alive", "30m"),
@@ -112,12 +113,13 @@ def run_llm_processor(in_queue, out_queue, args):
             raise RuntimeError(f"OpenAI API error {response.status_code}: {detail}")
         return response.json()["choices"][0]["message"]["content"].strip()
 
-    def call_ollama(prompt, temperature):
+    def call_ollama(prompt, temperature, system=None):
         response = requests.post(
             getattr(args, "post_correct_ollama_url", "http://127.0.0.1:11434/api/generate"),
             json={
                 "model": args.post_correct_model,
                 "prompt": prompt,
+                "system": system or "",
                 "stream": False,
                 "options": {"temperature": temperature},
                 "keep_alive": getattr(args, "post_correct_keep_alive", "30m"),
@@ -133,7 +135,13 @@ def run_llm_processor(in_queue, out_queue, args):
                 if not api_key:
                     raise RuntimeError("OPENAI_API_KEY is not set")
                 return call_openai(messages)
-            return call_ollama(prompt, temperature)
+            system = ""
+            if messages:
+                for message in messages:
+                    if message.get("role") == "system":
+                        system = message.get("content", "")
+                        break
+            return call_ollama(prompt, temperature, system=system)
         except Exception as exc:
             if not llm_state[warn_key]:
                 label = "Paragraph LLM" if warn_key == "paragraph_warned" else "Line LLM"