diff --git a/farm_control.lua b/farm_control.lua
index e199bb4..9da6893 100644
--- a/farm_control.lua
+++ b/farm_control.lua
@@ -39,7 +39,8 @@ function check_levels (levels, src)
     end
     local needs_farming = {}
     for item, data in pairs(levels) do
-        if amounts[item] ~= nil and amounts[item] < data[1] then
+        if amounts[item] == nil then amounts[item] = 0 end
+        if amounts[item] < data[1] then
             if data[2] ~= nil then
                 table.insert(needs_farming, data[2])
             else