diff --git a/settlements/bookgen.lua b/settlements/bookgen.lua
index bcb9f39..be4253b 100644
--- a/settlements/bookgen.lua
+++ b/settlements/bookgen.lua
@@ -87,7 +87,9 @@ minetest.register_abm({
 			local book = town_def.generate_book(closest_settlement.pos, town_name)
 			if book then
 				inv:add_item("books", book)
-				bookshelf_on_construct(pos) -- this should safely update the bookshelf's infotext without disturbing its contents
+				if bookshelf_on_construct then
+					bookshelf_on_construct(pos) -- this should safely update the bookshelf's infotext without disturbing its contents
+				end
 			end
 		end
 	end,
diff --git a/settlements/mod.conf b/settlements/mod.conf
index 93f7391..13c702a 100644
--- a/settlements/mod.conf
+++ b/settlements/mod.conf
@@ -1,4 +1,4 @@
 name = settlements
 description = API for adding small settlements to map generation.
 depends = named_waypoints
-optional_depends = commoditymarket, intllib
+optional_depends = commoditymarket, intllib, default