diff --git a/API.md b/API.md
index e03a0e2..d9cf161 100644
--- a/API.md
+++ b/API.md
@@ -171,3 +171,12 @@ Opens the Crafting Guide with the current filter applied.
    * `player_name`: string param.
    * `item`: optional, string param. If set, this item is pre-selected. If the item does not exist or has no recipe, use the player's previous selection. By default, player's previous selection is used
    * `show_usages`: optional, boolean param. If true, show item usages.
+
+#### `craftguide.group_stereotypes`
+
+This is the table indexing the item groups by stereotypes.
+You can add a stereotype like so:
+
+```Lua
+craftguide.group_stereotypes.radioactive = "mod:item"
+```
diff --git a/init.lua b/init.lua
index cd85f77..7236fe9 100644
--- a/init.lua
+++ b/init.lua
@@ -54,7 +54,7 @@ local FMT = {
 	item_image_button = "item_image_button[%f,%f;%f,%f;%s;%s;%s]",
 }
 
-local group_stereotypes = {
+craftguide.group_stereotypes = {
 	wool         = "wool:white",
 	dye          = "dye:white",
 	water_bucket = "bucket:bucket_water",
@@ -373,9 +373,11 @@ local function groups_to_item(groups)
 	if #groups == 1 then
 		local group = groups[1]
 		local def_gr = "default:" .. group
+		local stereotypes = craftguide.group_stereotypes
+		local stereotype = stereotypes and stereotypes[group]
 
-		if group_stereotypes[group] then
-			return group_stereotypes[group]
+		if stereotype then
+			return stereotype
 		elseif reg_items[def_gr] then
 			return def_gr
 		end