diff --git a/mods/MAPGEN/mcl_structures/ruined_portal.lua b/mods/MAPGEN/mcl_structures/ruined_portal.lua
index 0f7df6686..ef8c806ca 100644
--- a/mods/MAPGEN/mcl_structures/ruined_portal.lua
+++ b/mods/MAPGEN/mcl_structures/ruined_portal.lua
@@ -12,7 +12,7 @@ end
 
 local def = {
 	place_on = {"group:grass_block","group:dirt","mcl_core:dirt_with_grass","group:grass_block","group:sand","group:grass_block_snow","mcl_core:snow"},
-	fill_ratio = 0.01,
+	fill_ratio = 0.006,
 	flags = "place_center_x, place_center_z, all_floors",
 	solid_ground = true,
 	make_foundation = true,