diff --git a/scripts/bench_hmmt.py b/scripts/bench_hmmt.py
index 9be1b68..dd7ce92 100644
--- a/scripts/bench_hmmt.py
+++ b/scripts/bench_hmmt.py
@@ -21,7 +21,7 @@ _HMMT_2025_SUBSET = [
     {
         "id": "hmmt-1",
         "question": "Find the number of positive integers n <= 100 such that n^2 + n is divisible by 6.",
-        "answer": "100",
+        "answer": "66",
     },
     {
         "id": "hmmt-2",
@@ -41,7 +41,7 @@ _HMMT_2025_SUBSET = [
     {
         "id": "hmmt-5",
         "question": "What is the remainder when 2^100 is divided by 125?",
-        "answer": "76",
+        "answer": "1",
     },
 ]
 
diff --git a/src/markovian_rsa_mlx/config.py b/src/markovian_rsa_mlx/config.py
index 3d10bf2..212d071 100644
--- a/src/markovian_rsa_mlx/config.py
+++ b/src/markovian_rsa_mlx/config.py
@@ -27,6 +27,7 @@ class RSAConfig:
     memory_fraction: float = 0.80
     max_context_tokens: int | None = None
     aggregation_template: Literal["zaya_v1"] = "zaya_v1"
+    enable_thinking: bool = False
     answer_selection: Literal["first_final_candidate"] = "first_final_candidate"
 
     def __post_init__(self) -> None:
diff --git a/src/markovian_rsa_mlx/orchestrator.py b/src/markovian_rsa_mlx/orchestrator.py
index c7e39e1..61f6590 100644
--- a/src/markovian_rsa_mlx/orchestrator.py
+++ b/src/markovian_rsa_mlx/orchestrator.py
@@ -150,7 +150,7 @@ class MarkovianRSAOrchestrator:
         parent_ids_per_trace: list[list[str]] = []
         if is_round_0:
             messages = build_round_0_messages(original_prompt)
-            prompt_ids = self._render_chat(messages)
+            prompt_ids = self._render_chat(messages, enable_thinking=cfg.enable_thinking)
             prompts_token_ids = [prompt_ids for _ in range(cfg.parallel)]
             parent_ids_per_trace = [[] for _ in range(cfg.parallel)]
         else:
@@ -171,7 +171,7 @@ class MarkovianRSAOrchestrator:
                     original_prompt=original_prompt, tails=tails,
                     template=cfg.aggregation_template,
                 )
-                prompt_ids = self._render_chat(messages)
+                prompt_ids = self._render_chat(messages, enable_thinking=cfg.enable_thinking)
                 child_trace_id = f"r{round_idx}-t{trace_idx}-{run_id[:6]}"
                 audit.write(AggregationPromptEvent(
                     run_id=run_id, round=round_idx, trace_id=child_trace_id,
@@ -217,10 +217,10 @@ class MarkovianRSAOrchestrator:
         round_elapsed = time.time() - round_t0
         return records, round_elapsed
 
-    def _render_chat(self, messages: list[dict[str, str]]) -> list[int]:
+    def _render_chat(self, messages: list[dict[str, str]], *, enable_thinking: bool) -> list[int]:
         """Apply ZAYA chat template and return token ids."""
         rendered = self.tokenizer.apply_chat_template(
-            messages, add_generation_prompt=True, enable_thinking=True,
+            messages, add_generation_prompt=True, enable_thinking=enable_thinking,
         )
         if isinstance(rendered, str):
             return self.tokenizer.encode(rendered)
diff --git a/tests/test_config.py b/tests/test_config.py
index 6db91e3..f46bc82 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -74,3 +74,13 @@ def test_final_tokens_zero_rejected():
 def test_final_tokens_negative_rejected():
     with pytest.raises(ValueError, match="final_tokens must be positive"):
         RSAConfig(final_tokens=-1)
+
+
+def test_enable_thinking_default_false():
+    cfg = RSAConfig()
+    assert cfg.enable_thinking is False
+
+
+def test_enable_thinking_can_be_enabled():
+    cfg = RSAConfig(enable_thinking=True)
+    assert cfg.enable_thinking is True