diff --git a/backend/app/dialog/tree.py b/backend/app/dialog/tree.py
index a78be54..9b4ee23 100644
--- a/backend/app/dialog/tree.py
+++ b/backend/app/dialog/tree.py
@@ -22,6 +22,7 @@ from app.domain.events import Mood
 log = logging.getLogger(__name__)
 
 LIBRARY = Path(__file__).resolve().parents[3] / "scenarios" / "pregenerated"
+_Loader = getattr(yaml, "CSafeLoader", yaml.SafeLoader)
 
 
 def table_path(scenario_id: str) -> Path:
@@ -40,7 +41,9 @@ class TreeCaller:
     """
 
     def __init__(self, scenario_id: str) -> None:
-        self._table = yaml.safe_load(table_path(scenario_id).read_text(encoding="utf-8")) or {}
+        self._table = yaml.load(
+            table_path(scenario_id).read_text(encoding="utf-8"), Loader=_Loader
+        ) or {}
         self._fallback = TemplateCaller()
         self._turn = 0
         self.misses = 0
diff --git a/backend/app/scenarios/loader.py b/backend/app/scenarios/loader.py
index 7645088..eaad57b 100644
--- a/backend/app/scenarios/loader.py
+++ b/backend/app/scenarios/loader.py
@@ -14,6 +14,10 @@ from app.domain import ekp
 from app.domain.classifiers import DDS_BY_INCIDENT
 from app.scenarios.schema import ChecklistItem, Scenario
 
+# Библиотека читается на каждом старте приложения, а в тестах — на каждый
+# TestClient: чистый Python-парсер тратит на неё ~1.7 с, libyaml — ~0.2 с.
+_Loader = getattr(yaml, "CSafeLoader", yaml.SafeLoader)
+
 
 class ScenarioError(Exception):
     """Ошибка библиотеки. Текст пишется для методиста, не для программиста."""
@@ -21,7 +25,7 @@ class ScenarioError(Exception):
 
 def _read_yaml(path: Path) -> dict:
     try:
-        data = yaml.safe_load(path.read_text(encoding="utf-8"))
+        data = yaml.load(path.read_text(encoding="utf-8"), Loader=_Loader)
     except yaml.YAMLError as exc:
         raise ScenarioError(f"{path.name}: битый YAML — {exc}") from exc
     if not isinstance(data, dict):