diff --git a/libworld.lua b/libworld.lua
index 019215e..5fc1c76 100644
--- a/libworld.lua
+++ b/libworld.lua
@@ -2,6 +2,7 @@
 -- Author: Github/Kiritow
 
 local component=require("component")
+local computer=require("computer")
 
 -- Copy an area. returns a table contains area info.
 -- Can be serialized and stored in files.