diff --git a/DynDNS/dyndns.lua b/DynDNS/dyndns.lua
index 05fdb31..d615752 100644
--- a/DynDNS/dyndns.lua
+++ b/DynDNS/dyndns.lua
@@ -178,6 +178,7 @@ for key,value in pairs(array) do
 end
 
 config_file = read_file(output_file)
+if config_file == nil then config_file = "" end
 
 c1 = sort_table(split(config_file, "\r\n"))
 c2 = sort_table(split(config, "\r\n"))