diff --git a/init.lua b/init.lua
index 658f2a2..16aa90a 100644
--- a/init.lua
+++ b/init.lua
@@ -5,28 +5,12 @@ local modpath = minetest.get_modpath(modname)
 
 dofile(modpath .. "/api.lua")
 
-local depends = (function()
-	local file = io.open(modpath .. "/depends.txt")
-	if not file then
-		return {}
-	end
-
-	local depends = {}
-	for line in file:lines() do
-		if line:sub(-1) == "?" then
-			line = line:sub(1, -2)
-		end
-		depends[line] = true
-	end
-
-	file:close()
-
-	return depends
-end)()
+local modutils = dofile(modpath .. "/modutils.lua")
+local depmod = modutils.get_depend_checker(modname)
 
 local function filter(name, def)
 	-- disable carpets from loaded modules but not defined in dependency
-	if not depends[def.mod_origin] then
+	if not depmod:check_depend(def.mod_origin) then
 		return false
 	end
 
diff --git a/modutils.lua b/modutils.lua
new file mode 100644
index 0000000..b7634c5
--- /dev/null
+++ b/modutils.lua
@@ -0,0 +1,42 @@
+local modutils = {}
+
+local function check_depend(this, modname)
+	local depends = this.depends
+	if depends[modname] then
+		return true
+	else
+		return false
+	end
+end
+
+function modutils.get_depend_checker(modname)
+	-- Definition of returning object attributes
+	local this = { }
+	this.modname = modname
+	this.depends = {} -- depends.txt parsed
+	this.check_depend = check_depend -- method
+
+	-- get module path
+	local modpath = minetest.get_modpath(modname)
+	if not modpath then
+		return nil -- module not found
+	end
+
+	-- read the depends file
+	local dependsfile = io.open(modpath .. "/depends.txt")
+	if not dependsfile then
+		return nil
+	end
+
+	-- parse the depends file
+	for line in dependsfile:lines() do
+		if line:sub(-1) == "?" then
+			line = line:sub(1, -2)
+		end
+		this.depends[line] = true
+	end
+
+	return this
+end
+
+return modutils