diff --git a/tests/test_model_validation_unit.py b/tests/test_model_validation_unit.py
index beae233..e4f15a7 100644
--- a/tests/test_model_validation_unit.py
+++ b/tests/test_model_validation_unit.py
@@ -12,18 +12,16 @@ import hashlib
 
 import pytest
 
-# -- Prediction Snapshot Writer --
-from services.validation.prediction_snapshot import (
-    MAX_SINGLE_DOCUMENT_WEIGHT,
-    compute_canonical_evidence_key,
-    compute_contribution_scores,
+# -- Quality Gate --
+from services.trading.model_quality_gate import (
+    QualityGateConfig,
+    _evaluate_thresholds,
 )
 
-# -- Outcome Evaluator --
-from services.validation.outcome_evaluator import (
-    _compute_return,
-    _is_direction_correct,
-    _is_profitable,
+# -- Calibration Engine --
+from services.validation.calibration import (
+    compute_adjusted_evidence_weight,
+    compute_source_reliability,
 )
 
 # -- Metrics Engine --
@@ -34,19 +32,20 @@ from services.validation.metrics import (
     compute_rank_information_coefficient,
 )
 
-# -- Calibration Engine --
-from services.validation.calibration import (
-    compute_adjusted_evidence_weight,
-    compute_source_reliability,
+# -- Outcome Evaluator --
+from services.validation.outcome_evaluator import (
+    _compute_return,
+    _is_direction_correct,
+    _is_profitable,
 )
 
-# -- Quality Gate --
-from services.trading.model_quality_gate import (
-    QualityGateConfig,
-    _evaluate_thresholds,
+# -- Prediction Snapshot Writer --
+from services.validation.prediction_snapshot import (
+    MAX_SINGLE_DOCUMENT_WEIGHT,
+    compute_canonical_evidence_key,
+    compute_contribution_scores,
 )
 
-
 # ===================================================================
 # 8.2 — Prediction Snapshot Writer unit tests
 # Requirements: 1.1, 2.3, 2.4, 2.5, 3.3
diff --git a/tests/test_pbt_model_validation.py b/tests/test_pbt_model_validation.py
index 7da1764..1e7e6b9 100644
--- a/tests/test_pbt_model_validation.py
+++ b/tests/test_pbt_model_validation.py
@@ -176,7 +176,6 @@ from services.validation.metrics import (
     compute_information_coefficient,
 )
 
-
 # ---------------------------------------------------------------------------
 # Property 1: Calibration Error Range and Round-Trip
 # Validates: Requirements 5.1, 5.3, 17.1
@@ -492,7 +491,6 @@ def test_source_reliability_convergence(observed_win_rate: float) -> None:
 # ---------------------------------------------------------------------------
 
 from services.trading.model_quality_gate import (
-    GateThresholdResult,
     QualityGateConfig,
     _evaluate_thresholds,
 )