diff --git a/colddb.lua b/colddb.lua
index a6cf88f..593a93e 100644
--- a/colddb.lua
+++ b/colddb.lua
@@ -100,6 +100,9 @@ function colddb.Colddb(dir)
 	
 	local function save_table(name, _table)
 		minetest.log(string.format("%s/%s.cold", directory, name))
+		if save_table == nil or name == nil then
+			return false
+		end
 		return minetest.safe_file_write(string.format("%s/%s.cold", directory, name), minetest.serialize(_table))
 	end