diff --git a/alembic/versions/033_regime_fundamental_observations.py b/alembic/versions/033_regime_fundamental_observations.py
index 1352add..c2d24f7 100644
--- a/alembic/versions/033_regime_fundamental_observations.py
+++ b/alembic/versions/033_regime_fundamental_observations.py
@@ -48,14 +48,17 @@ def upgrade() -> None:
         sa.Column("fetched_at", sa.DateTime(timezone=True), nullable=False),
         sa.Column("created_at", sa.DateTime(timezone=True), nullable=False),
         sa.PrimaryKeyConstraint("id"),
-        sa.UniqueConstraint(
-            "effective_date", name="uq_regime_fundamental_observations_effective_date"
-        ),
     )
+    # One unique index, not a unique constraint plus a plain index: the model
+    # declares `unique=True, index=True`, which SQLAlchemy renders as exactly
+    # this. The constraint-plus-index pairing worked but left a redundant second
+    # index on the column and a permanent metadata diff for autogenerate to keep
+    # trying to reconcile. Matches RegimeSnapshot.date, the sibling table.
     op.create_index(
         "ix_regime_fundamental_observations_effective_date",
         "regime_fundamental_observations",
         ["effective_date"],
+        unique=True,
     )
 
 
diff --git a/tests/unit/test_event_study.py b/tests/unit/test_event_study.py
index 0393923..dec509e 100644
--- a/tests/unit/test_event_study.py
+++ b/tests/unit/test_event_study.py
@@ -5,8 +5,6 @@ from __future__ import annotations
 from copy import deepcopy
 from datetime import date, timedelta
 
-import pytest
-
 from app.services.breadth_service import _breadth_from_closes, compute_divergence_series
 from app.services.event_study_service import (
     MIN_EVENTS_FOR_CONFIDENCE,