diff --git a/game/tower.odin b/game/tower.odin
index 90c6c32..1e5e037 100644
--- a/game/tower.odin
+++ b/game/tower.odin
@@ -56,6 +56,7 @@ TOWER_ARCHETYPES: [Tower_Kind]Tower_Archetype = {
 		cost = 80,
 		footprint_w = 2,
 		footprint_h = 2,
+		max_upgrade = 1,
 		upgrade_cost = 40,
 		damage_per_level = 3,
 		range_per_level = 8,
@@ -69,6 +70,7 @@ TOWER_ARCHETYPES: [Tower_Kind]Tower_Archetype = {
 		cost = 65,
 		footprint_w = 1,
 		footprint_h = 1,
+		max_upgrade = 1,
 		upgrade_cost = 40,
 		damage_per_level = 3,
 		range_per_level = 8,