diff --git a/mods/ra/rules/trees.yaml b/mods/ra/rules/trees.yaml
index 8f72b52225..a053478e26 100644
--- a/mods/ra/rules/trees.yaml
+++ b/mods/ra/rules/trees.yaml
@@ -127,6 +127,7 @@ MINE:
 	SeedsResource:
 	RadarColorFromTerrain:
 		Terrain: Ore
+	BelowUnits:
 
 BOXES01:
 	Inherits: ^Tree