diff --git a/abms.lua b/abms.lua
index a5d2d7e..90e86ec 100644
--- a/abms.lua
+++ b/abms.lua
@@ -71,7 +71,7 @@ minetest.register_globalstep(function(dtime)
 	local out = io.open(fun_caves.world..'/fun_caves_data.txt','w')	
 	if out then
 		out:write(minetest.serialize(fun_caves.db))
-		out.close()
+		out:close()
 	end
 
 	-- Promote mobs based on spawn position