diff --git a/api/alembic/versions/sql/0050_form4_sheet_sum.sql b/api/alembic/versions/sql/0050_form4_sheet_sum.sql
index 5261c66..46bea3d 100644
--- a/api/alembic/versions/sql/0050_form4_sheet_sum.sql
+++ b/api/alembic/versions/sql/0050_form4_sheet_sum.sql
@@ -7,6 +7,7 @@ CREATE OR REPLACE FUNCTION v3.v_form4_sheet_jsonb(p_form_id integer, p_sheet cha
  RETURNS TABLE(row_type character varying, depth integer, sort_order bigint, data jsonb)
  LANGUAGE sql
  STABLE
+ SET jit TO 'off'  -- оценка плана выше порога JIT, компиляция дороже выполнения (AURORA-1846)
 AS $function$
   -- ═══ 1. Базовые INPUT-строки с расширенной иерархией ═══════════════════════
   WITH inp_raw AS (
diff --git a/api/tests/integration/test_form4_sheet_sums.py b/api/tests/integration/test_form4_sheet_sums.py
index b3a35bf..7b8423a 100644
--- a/api/tests/integration/test_form4_sheet_sums.py
+++ b/api/tests/integration/test_form4_sheet_sums.py
@@ -342,3 +342,14 @@ def test_cell_patch_returns_updated_ancestor_sums(f4, client):
     _, groups, items, _ = check_sums(f4)
     assert Decimal(str(groups[prog]["plan"]["q1"])) == 25
     assert Decimal(str(items[prj]["plan"]["q1"])) == 25
+
+
+def test_jit_off_on_sheet_jsonb(f4):
+    """AURORA-1846: v_form4_sheet_jsonb выполняется с jit=off (оценка плана выше порога JIT)."""
+    rows = f4.sql(
+        """SELECT p.proname, COALESCE(p.proconfig, '{}') FROM pg_proc p
+             JOIN pg_namespace n ON n.oid = p.pronamespace
+            WHERE n.nspname = 'v3' AND p.proname = 'v_form4_sheet_jsonb'"""
+    )
+    assert len(rows) == 1, rows
+    assert "jit=off" in rows[0][1], f"нет SET jit = off: {rows[0][1]}"