diff --git a/tradein-mvp/backend/scripts/backtest_estimator.py b/tradein-mvp/backend/scripts/backtest_estimator.py
index f77eb0c8..1a4b1645 100644
--- a/tradein-mvp/backend/scripts/backtest_estimator.py
+++ b/tradein-mvp/backend/scripts/backtest_estimator.py
@@ -2633,7 +2633,9 @@ def _write_fixture(
 ) -> None:
     """Freeze captured per-deal replay records into a committed JSON fixture.
 
-    ``settings_at_capture`` records every ``estimate_*`` Settings field as an
+    ``settings_at_capture`` records every ``estimate_*`` Settings field plus the
+    estimator's numeric module constants (#1970: калибровочные пороги переехали из
+    Settings в код — без них снимок не говорит, с какими порогами захватили) as an
     informational snapshot (NOT consulted by ``replay_fixture``). A final
     recursive ``_sanitize_json`` pass guarantees the whole document is finite +
     JSON-plain before ``json.dump(allow_nan=False)``.
@@ -2643,6 +2645,11 @@ def _write_fixture(
         for name in sorted(type(est.settings).model_fields)
         if name.startswith("estimate_")
     }
+    settings_at_capture.update(
+        (name, _sanitize_json(value))
+        for name, value in sorted(vars(est.m).items())
+        if name.isupper() and isinstance(value, int | float)
+    )
     fixture = {
         "schema_version": FIXTURE_SCHEMA_VERSION,
         "engine": "full",
diff --git a/tradein-mvp/backend/tests/test_backtest_fixture_roundtrip.py b/tradein-mvp/backend/tests/test_backtest_fixture_roundtrip.py
index 4e7ee9e4..b648afba 100644
--- a/tradein-mvp/backend/tests/test_backtest_fixture_roundtrip.py
+++ b/tradein-mvp/backend/tests/test_backtest_fixture_roundtrip.py
@@ -297,3 +297,17 @@ def test_load_fixture_plain_and_gzip_roundtrip() -> None:
         m_plain = bt.replay_fixture(loaded_plain)
         m_gz = bt.replay_fixture(loaded_gz)
         assert json.dumps(m_plain, sort_keys=True) == json.dumps(m_gz, sort_keys=True)
+
+
+def test_write_fixture_records_engine_constants(tmp_path: Path) -> None:
+    """#1970: пороги движка — константы estimator.py, снимок фикстуры обязан их нести."""
+    est = bt._import_estimator_full()
+    out = tmp_path / "fixture.json"
+    bt._write_fixture(str(out), capture=[], since="2026-09-01", est=est)
+    snap = json.loads(out.read_text(encoding="utf-8"))["settings_at_capture"]
+    assert {
+        k: snap.get(k)
+        for k in ("CORRIDOR_CLAMP_MIN_N", "CORRIDOR_CLAMP_SLACK", "QUARTER_INDEX_MIN_N_DEALS")
+    } == {"CORRIDOR_CLAMP_MIN_N": 10, "CORRIDOR_CLAMP_SLACK": 0.4, "QUARTER_INDEX_MIN_N_DEALS": 10}
+    assert snap.get("SB_ROOMS_MATCH_BOOST") == 1.6
+    assert "estimate_pi_low_mult" in snap  # поля Settings по-прежнему в снимке