diff --git a/nature_classic/global_function.lua b/nature_classic/global_function.lua
index ec78942..45e567f 100644
--- a/nature_classic/global_function.lua
+++ b/nature_classic/global_function.lua
@@ -43,7 +43,7 @@ end
 
 function nature:grow_node(pos, nodename)
     if pos ~= nil then
-        local light_enough = minetest.get_node_light(pos, nil)
+        local light_enough = (minetest.get_node_light(pos, nil) or 0)
                 >= nature.minimum_growth_light 
 
         if is_not_young(pos) and light_enough then