diff --git a/scripts/yoga_engine.py b/scripts/yoga_engine.py
index 939e015a..7fe6e2fd 100644
--- a/scripts/yoga_engine.py
+++ b/scripts/yoga_engine.py
@@ -744,6 +744,21 @@ class YogaEngine:
                     "effects_en": list(rule.get("effects_en") or rule.get("effects", [])),
                     "strength_en": rule.get("strength_en") if strength == rule.get("strength") and rule.get("strength_en") else STRENGTH_EN.get(str(strength), str(strength)),
                 }
+                # Budha-Aditya is a conjunction witness, but a combust
+                # Mercury must not be presented as an unqualified full yoga
+                # (upstream yinduzhanxing 994638f0; sync5 U7).
+                if rule.get('id') == 'budhaditya_yoga':
+                    mercury = ctx.planets.get('Mercury') or {}
+                    if mercury.get('combust') is True:
+                        entry['condition_status'] = 'combustion_requires_review'
+                        entry['traditional_effects'] = entry['effects']
+                        entry['effects'] = []
+                        entry['strength'] = 'conditional'
+                        entry['combustion_witness'] = {
+                            'planet': 'Mercury',
+                            'combust': True,
+                            'claim_boundary': 'Do not treat Budha-Aditya as an unqualified benefic result while Mercury is combust.'
+                        }
                 dedup_key = rule.get("dedup_key") or rule["name"]
                 dedup_val = f"{dedup_key}:{m.get('combination', '')}"
                 if dedup_val in seen_dedup:
diff --git a/tests/test_budhaditya_combustion_gate.py b/tests/test_budhaditya_combustion_gate.py
new file mode 100644
index 00000000..edf943c8
--- /dev/null
+++ b/tests/test_budhaditya_combustion_gate.py
@@ -0,0 +1,29 @@
+from scripts.yoga_engine import YogaEngine
+
+
+def test_budhaditya_with_combust_mercury_is_conditional():
+    engine = YogaEngine('references/yoga_rules.json')
+    planets = {
+        'Sun': {'sign': 'Aries', 'house': 1},
+        'Mercury': {'sign': 'Aries', 'house': 1, 'combust': True},
+    }
+    rows = [row for row in engine.detect(planets, 'Aries') if row['rule_id'] == 'budhaditya_yoga']
+    assert len(rows) == 1
+    row = rows[0]
+    assert row['condition_status'] == 'combustion_requires_review'
+    assert row['effects'] == []
+    assert row['traditional_effects']
+    assert row['strength'] == 'conditional'
+    assert row['combustion_witness']['planet'] == 'Mercury'
+
+
+def test_budhaditya_without_combustion_keeps_traditional_effects():
+    engine = YogaEngine('references/yoga_rules.json')
+    planets = {
+        'Sun': {'sign': 'Aries', 'house': 1},
+        'Mercury': {'sign': 'Aries', 'house': 1, 'combust': False},
+    }
+    rows = [row for row in engine.detect(planets, 'Aries') if row['rule_id'] == 'budhaditya_yoga']
+    assert len(rows) == 1
+    assert rows[0]['effects']
+    assert 'combustion_witness' not in rows[0]