diff --git a/api.lua b/api.lua
index 59296db..872ce32 100644
--- a/api.lua
+++ b/api.lua
@@ -25,7 +25,8 @@ minetest.after(0.01, function()
 						for _,chk in pairs(recipe.items) do
 							local groupchk = string.find(chk, "group:")
 							if (not groupchk and not minetest.registered_items[chk])
-							  or (groupchk and not unified_inventory.get_group_item(string.gsub(chk, "group:", "")).item) then
+							  or (groupchk and not unified_inventory.get_group_item(string.gsub(chk, "group:", "")).item)
+							  or minetest.get_item_group(chk, "exclude_from_craft_guide") ~= 0 then
 								unknowns = true
 							end
 						end