diff --git a/category.lua b/category.lua
index 8807a48..d10a628 100644
--- a/category.lua
+++ b/category.lua
@@ -1,3 +1,4 @@
+local S = minetest.get_translator("unified_inventory")
 
 unified_inventory.registered_categories = {}
 unified_inventory.registered_category_items = {}
@@ -7,13 +8,13 @@ function update_category_list()
 	local category_list = {}
 	table.insert(category_list, {
 		name = "all",
-		label = "All Items",
+		label = S("All Items"),
 		symbol = "ui_category_all.png",
 		index = -2,
 	})
 	table.insert(category_list, {
 		name = "uncategorized",
-		label = "Misc. Items",
+		label = S("Misc. Items"),
 		symbol = "ui_category_none.png",
 		index = -1,
 	})
diff --git a/default-categories.lua b/default-categories.lua
index 2b71f60..57d3e88 100644
--- a/default-categories.lua
+++ b/default-categories.lua
@@ -1,27 +1,28 @@
+local S = minetest.get_translator("unified_inventory")
 
 unified_inventory.register_category('plants', {
 	symbol = "flowers:tulip",
-	label = "Plant Life"
+	label = S("Plant Life")
 })
 unified_inventory.register_category('building', {
 	symbol = "default:brick",
-	label = "Building Materials"
+	label = S("Building Materials")
 })
 unified_inventory.register_category('tools', {
 	symbol = "default:pick_diamond",
-	label = "Tools"
+	label = S("Tools")
 })
 unified_inventory.register_category('minerals', {
 	symbol = "default:iron_lump",
-	label = "Minerals and Metals"
+	label = S("Minerals and Metals")
 })
 unified_inventory.register_category('environment', {
 	symbol = "default:dirt_with_grass",
-	label = "Environment and Worldgen"
+	label = S("Environment and Worldgen")
 })
 unified_inventory.register_category('lighting', {
 	symbol = "default:torch",
-	label = "Lighting"
+	label = S("Lighting")
 })
 
 
diff --git a/internal.lua b/internal.lua
index b62d550..1c096a6 100644
--- a/internal.lua
+++ b/internal.lua
@@ -36,7 +36,7 @@ local function formspec_button(ui_peruser, name, image, offset, pos, scale, labe
 		(offset.x or offset[1]) + ( ui_peruser.btn_spc * (pos.x or pos[1]) ) + spc,
 		(offset.y or offset[2]) + ( ui_peruser.btn_spc * (pos.y or pos[2]) ) + spc,
 		size, size, image, name) ..
-		string.format("tooltip[%s;%s]", name, F(S(label or name)))
+		string.format("tooltip[%s;%s]", name, F(label or name))
 end
 
 function ui.get_formspec(player, page)
@@ -157,12 +157,12 @@ function ui.get_formspec(player, page)
 	end
 	if category_count > ui_peruser.pagecols and scroll_offset > 0 then
 		-- prev
-		formspec[n] = formspec_button(ui_peruser, "prev_category", "ui_left_icon.png", categories_scroll_pos, {ui_peruser.pagecols - 2, 0}, 0.8, "Scroll categories left")
+		formspec[n] = formspec_button(ui_peruser, "prev_category", "ui_left_icon.png", categories_scroll_pos, {ui_peruser.pagecols - 2, 0}, 0.8, S("Scroll categories left"))
 		n = n + 1
 	end
 	if category_count > ui_peruser.pagecols and category_count - scroll_offset > ui_peruser.pagecols then
 		-- next
-		formspec[n] = formspec_button(ui_peruser, "next_category", "ui_right_icon.png", categories_scroll_pos, {ui_peruser.pagecols - 1, 0}, 0.8, "Scroll categories right")
+		formspec[n] = formspec_button(ui_peruser, "next_category", "ui_right_icon.png", categories_scroll_pos, {ui_peruser.pagecols - 1, 0}, 0.8, S("Scroll categories right"))
 		n = n + 1
 	end