diff --git a/src/main/kotlin/ru/dbotthepony/mc/otm/worldgen/EnhancedPlacedFeature.kt b/src/main/kotlin/ru/dbotthepony/mc/otm/worldgen/EnhancedPlacedFeature.kt
index 3f9483e91..d6eaf6c68 100644
--- a/src/main/kotlin/ru/dbotthepony/mc/otm/worldgen/EnhancedPlacedFeature.kt
+++ b/src/main/kotlin/ru/dbotthepony/mc/otm/worldgen/EnhancedPlacedFeature.kt
@@ -5,7 +5,6 @@ import com.github.benmanes.caffeine.cache.Caffeine
 import com.github.benmanes.caffeine.cache.Scheduler
 import com.mojang.serialization.Codec
 import com.mojang.serialization.codecs.RecordCodecBuilder
-import it.unimi.dsi.fastutil.ints.Int2ObjectRBTreeMap
 import it.unimi.dsi.fastutil.io.FastByteArrayOutputStream
 import it.unimi.dsi.fastutil.objects.ObjectArrayList
 import it.unimi.dsi.fastutil.objects.ObjectRBTreeSet
@@ -31,6 +30,7 @@ import ru.dbotthepony.mc.otm.worldgen.placement.EnhancedPlacement
 import java.io.DataOutputStream
 import java.time.Duration
 import java.util.*
+import kotlin.collections.ArrayList
 import kotlin.math.sqrt
 
 object EnhancedPlacedFeature : Feature<EnhancedPlacedFeature.Config>(
@@ -58,12 +58,12 @@ object EnhancedPlacedFeature : Feature<EnhancedPlacedFeature.Config>(
 		val root: EnhancedPlacement,
 	) : FeatureConfiguration {
 		private class GeneratedChunk : EnhancedPlacementContext.Placer {
-			private data class Placement(val context: EnhancedPlacementContext, val positions: ObjectRBTreeSet<PlacementPos>, val feature: EnhancedFeature.Configured<*, *>)
+			private data class Placement(val context: EnhancedPlacementContext, val positions: TreeSet<PlacementPos>, val feature: EnhancedFeature.Configured<*, *>)
 			private val placed = LinkedList<Placement>()
 
 			override fun place(context: EnhancedPlacementContext, positions: List<PlacementPos>, feature: EnhancedFeature.Configured<*, *>) {
 				if (positions.isNotEmpty()) {
-					placed.add(Placement(context, ObjectRBTreeSet<PlacementPos>().also { it.addAll(positions) }, feature))
+					placed.add(Placement(context, TreeSet<PlacementPos>().also { it.addAll(positions) }, feature))
 				}
 			}
 
@@ -72,12 +72,12 @@ object EnhancedPlacedFeature : Feature<EnhancedPlacedFeature.Config>(
 				val pos = ChunkPos(context.origin())
 
 				for ((eContext, positions, feature) in placed) {
-					val itr = positions.iterator(PlacementPos(BlockPos(pos.minBlockX, Int.MIN_VALUE, pos.minBlockZ), emptyVariableMap))
+					val itr = positions.tailSet(PlacementPos(BlockPos(pos.minBlockX, Int.MIN_VALUE, pos.minBlockZ), emptyVariableMap)).iterator()
 
 					if (!itr.hasNext())
 						continue
 
-					val result = ObjectRBTreeSet<PlacementPos>()
+					val result = TreeSet<PlacementPos>()
 
 					for (placementPos in itr) {
 						if (SectionPos.blockToSectionCoord(placementPos.pos.x) != pos.x || SectionPos.blockToSectionCoord(placementPos.pos.z) != pos.z)
@@ -155,14 +155,21 @@ object EnhancedPlacedFeature : Feature<EnhancedPlacedFeature.Config>(
 			// between threads which lookup cache while it is being populated on neighbouring chunks
 			withIndex.shuffle(THREAD_LOCAL_RANDOM)
 
-			val instances = Int2ObjectRBTreeMap<GeneratedChunk>()
+			data class P(val i: Int, val v: GeneratedChunk) : Comparable<P> {
+				override fun compareTo(other: P): Int {
+					return i.compareTo(other.i)
+				}
+			}
+
+			val instances = ArrayList<P>()
+			instances.sort()
 
 			withIndex.forEach { (i, it) ->
-				instances.put(i, cache.get(it) { evaluate(context, it) })
+				instances.add(P(i, cache.get(it) { evaluate(context, it) }))
 			}
 
 			var any = false
-			instances.values.forEach { any = it.place(context) }
+			instances.forEach { any = it.v.place(context) }
 			return any
 		}
 	}
diff --git a/src/main/kotlin/ru/dbotthepony/mc/otm/worldgen/placement/EllipsoidPlacement.kt b/src/main/kotlin/ru/dbotthepony/mc/otm/worldgen/placement/EllipsoidPlacement.kt
index 069423002..4c293e12f 100644
--- a/src/main/kotlin/ru/dbotthepony/mc/otm/worldgen/placement/EllipsoidPlacement.kt
+++ b/src/main/kotlin/ru/dbotthepony/mc/otm/worldgen/placement/EllipsoidPlacement.kt
@@ -2,7 +2,6 @@ package ru.dbotthepony.mc.otm.worldgen.placement
 
 import com.mojang.serialization.MapCodec
 import com.mojang.serialization.codecs.RecordCodecBuilder
-import it.unimi.dsi.fastutil.objects.ObjectRBTreeSet
 import net.minecraft.core.BlockPos
 import net.minecraft.util.RandomSource
 import net.minecraft.util.valueproviders.FloatProvider
@@ -14,6 +13,7 @@ import ru.dbotthepony.mc.otm.core.collect.Vec3iHashStrategy
 import ru.dbotthepony.mc.otm.registry.data.MPlacementModifiers
 import ru.dbotthepony.mc.otm.worldgen.EnhancedPlacementContext
 import ru.dbotthepony.mc.otm.worldgen.PlacementPos
+import java.util.*
 import java.util.stream.Stream
 
 /**
@@ -61,9 +61,9 @@ data class EllipsoidPlacement(
 		require(yLength.minValue >= 1f) { "Bad ellipsoid y minimal size: $yLength" }
 	}
 
-	private fun evaluate(random: RandomSource, position: BlockPos): ObjectRBTreeSet<BlockPos> {
+	private fun evaluate(random: RandomSource, position: BlockPos): Set<BlockPos> {
 		val count = count.sample(random)
-		val results = ObjectRBTreeSet<BlockPos>(Vec3iHashStrategy)
+		val results = TreeSet<BlockPos>(Vec3iHashStrategy)
 
 		if (count <= 0)
 			return results