diff --git a/init.lua b/init.lua
index dc3fa98..89cc87e 100644
--- a/init.lua
+++ b/init.lua
@@ -366,16 +366,18 @@ function internal.clean_shape_def(def)
 end
 
 -- Get the most nearby cave biome
-function internal.closest_cave_biome(heat, humidity)
+function internal.closest_cave_biome(heat, humidity, pos)
     local biome = internal.default_biome()
     local d = internal.biome_def_distance(biome, heat, humidity)
 
     for _, def in pairs(noordstar_caves.registered_biomes) do
-        local new_d = internal.biome_def_distance(def, heat, humidity)
-
-        if new_d <= d then
-            biome = def
-            d = new_d
+        if internal.is_valid_pos(pos, def.minp, def.maxp) then
+            local new_d = internal.biome_def_distance(def, heat, humidity)
+    
+            if new_d <= d then
+                biome = def
+                d = new_d
+            end
         end
     end
 
@@ -383,16 +385,18 @@ function internal.closest_cave_biome(heat, humidity)
 end
 
 -- Get the most nearby cave shape
-function internal.closest_cave_shape(cnct, vrtcl)
+function internal.closest_cave_shape(cnct, vrtcl, y)
     local shape = internal.default_shape()
     local d = internal.shape_def_distance(shape, cnct, vrtcl)
 
     for key, def in pairs(noordstar_caves.registered_shapes) do
-        local new_d = internal.shape_def_distance(def, cnct, vrtcl)
-
-        if new_d <= d then
-            shape = def
-            d = new_d
+        if def.y_min <= y and y <= def.y_max then
+            local new_d = internal.shape_def_distance(def, cnct, vrtcl)
+    
+            if new_d <= d then
+                shape = def
+                d = new_d
+            end
         end
     end
 
@@ -516,7 +520,7 @@ function internal.flat_from_cave_bools(minp, maxp)
             local cnct = connectivity:get_index(i)
             local vrtcl = verticality:get_index(i)
 
-            local def = internal.closest_cave_shape(cnct, vrtcl)
+            local def = internal.closest_cave_shape(cnct, vrtcl, pos.y)
             
             return def.name
     end)
@@ -735,7 +739,7 @@ function internal.generate_caves(data, minp, maxp)
             local heat = heat_points:get_index(i)
             local humidity = humidity_points:get_index(i)
 
-            local def = internal.closest_cave_biome(heat, humidity)
+            local def = internal.closest_cave_biome(heat, humidity, pos)
 
             if nt == internal.node_types.floor then
                 place(def.node_floor)