diff --git a/api.lua b/api.lua
index 28eb8e3..1a38ed0 100644
--- a/api.lua
+++ b/api.lua
@@ -318,7 +318,7 @@ function mobs:register_spawn(name, nodes, max_light, min_light, chance, active_o
 	mobs.spawning_mobs[name] = true
 	minetest.register_abm({
 		nodenames = nodes,
-		neighbors = nodes,
+		neighbors = {"air"},
 		interval = 30,
 		chance = chance,
 		action = function(pos, node, _, active_object_count_wider)