diff --git a/mods/stairs/init.lua b/mods/stairs/init.lua
index c3ce160e..ea2933b6 100644
--- a/mods/stairs/init.lua
+++ b/mods/stairs/init.lua
@@ -22,6 +22,7 @@ local replace = minetest.setting_getbool("enable_stairs_replace_abm")
 -- Node will be called stairs:stair_<subname>
 
 function stairs.register_stair(subname, recipeitem, groups, images, description, sounds)
+	groups.stair = 1
 	minetest.register_node(":stairs:stair_" .. subname, {
 		description = description,
 		drawtype = "mesh",
@@ -111,6 +112,7 @@ end
 -- Node will be called stairs:slab_<subname>
 
 function stairs.register_slab(subname, recipeitem, groups, images, description, sounds)
+	groups.slab = 1
 	minetest.register_node(":stairs:slab_" .. subname, {
 		description = description,
 		drawtype = "nodebox",