diff --git a/mods/ts/rules/defaults.yaml b/mods/ts/rules/defaults.yaml
index e720daa09b..2b982b2b04 100644
--- a/mods/ts/rules/defaults.yaml
+++ b/mods/ts/rules/defaults.yaml
@@ -889,6 +889,7 @@
 		Damage: -2
 		DamageInterval: 16
 		Terrain: Tiberium, BlueTiberium
+		RequiresCondition: !inside-tunnel
 
 ^DamagedByVeins:
 	DamagedByTerrain@VEINS: