diff --git a/mods/nav/compass.lua b/mods/nav/compass.lua
index d148735..358ff1d 100644
--- a/mods/nav/compass.lua
+++ b/mods/nav/compass.lua
@@ -119,11 +119,13 @@ function step(dtime)
 	 local itemstack = inv:get_stack("main", i)
 	 local item = minetest.registered_items[itemstack:get_name()]
 	 
-	 if item.groups.nav_compass then
-	    inv:set_stack("main", i, ItemStack("nav:compass_"..dir))
+	 if item ~= nil then
+	    if item.groups.nav_compass then
+	       inv:set_stack("main", i, ItemStack("nav:compass_"..dir))
+	    end
 	 end
       end
    end
 end
 
-minetest.register_globalstep(step)
+minetest.register_globalstep(step)
\ No newline at end of file