diff --git a/src/main/java/de/bixilon/minosoft/data/world/World.kt b/src/main/java/de/bixilon/minosoft/data/world/World.kt
index 46eefed3b..e1f01f051 100644
--- a/src/main/java/de/bixilon/minosoft/data/world/World.kt
+++ b/src/main/java/de/bixilon/minosoft/data/world/World.kt
@@ -22,16 +22,15 @@ import de.bixilon.minosoft.data.world.biome.accessor.NullBiomeAccessor
 import de.bixilon.minosoft.data.world.light.WorldLightAccessor
 import de.bixilon.minosoft.gui.rendering.util.VecUtil.chunkPosition
 import de.bixilon.minosoft.gui.rendering.util.VecUtil.inChunkPosition
+import de.bixilon.minosoft.util.KUtil.synchronizedMapOf
 import glm_.vec2.Vec2i
 import glm_.vec3.Vec3i
-import java.util.*
-import java.util.concurrent.ConcurrentHashMap
 
 /**
  * Collection of chunks and more
  */
 class World : BiomeAccessor {
-    val chunks: MutableMap<Vec2i, Chunk> = Collections.synchronizedMap(ConcurrentHashMap())
+    val chunks: MutableMap<Vec2i, Chunk> = synchronizedMapOf()
     val entities = WorldEntities()
     var isHardcore = false
     var isRaining = false
@@ -47,16 +46,14 @@ class World : BiomeAccessor {
         return chunks[chunkLocation]?.getBlockState(blockPosition.inChunkPosition)
     }
 
+    @Synchronized
     fun getChunk(chunkPosition: Vec2i): Chunk? {
         return chunks[chunkPosition]
     }
 
+    @Synchronized
     fun getOrCreateChunk(chunkPosition: Vec2i): Chunk {
-        return chunks[chunkPosition] ?: run {
-            val chunk = Chunk()
-            chunks[chunkPosition] = chunk
-            chunk
-        }
+        return chunks.getOrPut(chunkPosition) { Chunk() }
     }
 
     fun setBlock(blockPosition: Vec3i, blockState: BlockState?) {
diff --git a/src/main/java/de/bixilon/minosoft/data/world/WorldEntities.kt b/src/main/java/de/bixilon/minosoft/data/world/WorldEntities.kt
index 4a87f40d5..1775f72d3 100644
--- a/src/main/java/de/bixilon/minosoft/data/world/WorldEntities.kt
+++ b/src/main/java/de/bixilon/minosoft/data/world/WorldEntities.kt
@@ -14,14 +14,14 @@
 package de.bixilon.minosoft.data.world
 
 import de.bixilon.minosoft.data.entities.entities.Entity
+import de.bixilon.minosoft.util.KUtil.synchronizedMapOf
 import java.util.*
-import java.util.concurrent.ConcurrentHashMap
 
 class WorldEntities : Iterable<Entity> {
-    private val idEntityMap: MutableMap<Int, Entity> = ConcurrentHashMap()
-    private val entityIdMap: MutableMap<Entity, Int> = ConcurrentHashMap()
-    private val entityUUIDMap: MutableMap<Entity, UUID> = ConcurrentHashMap()
-    private val uuidEntityMap: MutableMap<UUID, Entity> = ConcurrentHashMap()
+    private val idEntityMap: MutableMap<Int, Entity> = synchronizedMapOf()
+    private val entityIdMap: MutableMap<Entity, Int> = synchronizedMapOf()
+    private val entityUUIDMap: MutableMap<Entity, UUID> = synchronizedMapOf()
+    private val uuidEntityMap: MutableMap<UUID, Entity> = synchronizedMapOf()
 
 
     fun add(entityId: Int?, entityUUID: UUID?, entity: Entity) {
diff --git a/src/main/java/de/bixilon/minosoft/gui/rendering/RenderWindow.kt b/src/main/java/de/bixilon/minosoft/gui/rendering/RenderWindow.kt
index e484024a3..ca595160b 100644
--- a/src/main/java/de/bixilon/minosoft/gui/rendering/RenderWindow.kt
+++ b/src/main/java/de/bixilon/minosoft/gui/rendering/RenderWindow.kt
@@ -37,6 +37,9 @@ import de.bixilon.minosoft.protocol.network.connection.PlayConnection
 import de.bixilon.minosoft.protocol.packets.s2c.play.PositionAndRotationS2CP
 import de.bixilon.minosoft.protocol.protocol.ProtocolDefinition
 import de.bixilon.minosoft.util.CountUpAndDownLatch
+import de.bixilon.minosoft.util.KUtil.synchronizedListOf
+import de.bixilon.minosoft.util.KUtil.synchronizedMapOf
+import de.bixilon.minosoft.util.KUtil.synchronizedSetOf
 import de.bixilon.minosoft.util.Stopwatch
 import de.bixilon.minosoft.util.logging.Log
 import de.bixilon.minosoft.util.logging.LogMessageType
@@ -48,7 +51,6 @@ import org.lwjgl.opengl.GL
 import org.lwjgl.opengl.GL11.*
 import org.lwjgl.system.MemoryStack
 import org.lwjgl.system.MemoryUtil
-import java.util.concurrent.ConcurrentLinkedQueue
 
 class RenderWindow(
     val connection: PlayConnection,
@@ -73,16 +75,16 @@ class RenderWindow(
     private val screenshotTaker = ScreenshotTaker(this)
     val tintColorCalculator = TintColorCalculator(connection.world)
     val font = Font()
-    val textures = TextureArray(mutableListOf())
+    val textures = TextureArray(synchronizedListOf())
 
-    val rendererMap: MutableMap<ResourceLocation, Renderer> = mutableMapOf()
+    val rendererMap: MutableMap<ResourceLocation, Renderer> = synchronizedMapOf()
 
-    val renderQueue = ConcurrentLinkedQueue<Runnable>()
+    val renderQueue: MutableList<Runnable> = synchronizedListOf()
 
     lateinit var WHITE_TEXTURE: TextureLike
 
 
-    val screenResizeCallbacks: MutableSet<ScreenResizeCallback> = mutableSetOf(inputHandler.camera)
+    val screenResizeCallbacks: MutableSet<ScreenResizeCallback> = synchronizedSetOf(inputHandler.camera)
 
     var tickCount = 0L
     var lastTickTimer = System.currentTimeMillis()
@@ -331,12 +333,13 @@ class RenderWindow(
 
             // handle opengl context tasks, but limit it per frame
             var actionsDone = 0
+            val renderQueue = renderQueue.toList()
             for (renderQueueElement in renderQueue) {
                 if (actionsDone == RenderConstants.MAXIMUM_CALLS_PER_FRAME) {
                     break
                 }
                 renderQueueElement.run()
-                renderQueue.remove(renderQueueElement)
+                this.renderQueue.remove(renderQueueElement)
                 actionsDone++
             }
 
diff --git a/src/main/java/de/bixilon/minosoft/gui/rendering/chunk/WorldRenderer.kt b/src/main/java/de/bixilon/minosoft/gui/rendering/chunk/WorldRenderer.kt
index 7964e4d41..1fc0f6f47 100644
--- a/src/main/java/de/bixilon/minosoft/gui/rendering/chunk/WorldRenderer.kt
+++ b/src/main/java/de/bixilon/minosoft/gui/rendering/chunk/WorldRenderer.kt
@@ -40,13 +40,13 @@ import de.bixilon.minosoft.modding.event.events.*
 import de.bixilon.minosoft.protocol.network.connection.PlayConnection
 import de.bixilon.minosoft.protocol.protocol.ProtocolDefinition
 import de.bixilon.minosoft.util.KUtil.nullCast
+import de.bixilon.minosoft.util.KUtil.synchronizedMapOf
+import de.bixilon.minosoft.util.KUtil.synchronizedSetOf
 import de.bixilon.minosoft.util.MMath
 import de.bixilon.minosoft.util.logging.Log
 import glm_.vec2.Vec2i
 import glm_.vec3.Vec3i
 import org.lwjgl.opengl.GL11.glDepthMask
-import java.util.*
-import java.util.concurrent.ConcurrentHashMap
 
 class WorldRenderer(
     private val connection: PlayConnection,
@@ -56,9 +56,9 @@ class WorldRenderer(
     private val waterBlock = connection.mapping.blockRegistry.get(ResourceLocation("minecraft:water"))?.nullCast<FluidBlock>()
 
     override lateinit var shader: Shader
-    val allChunkSections: MutableMap<Vec2i, MutableMap<Int, ChunkMeshCollection>> = Collections.synchronizedMap(ConcurrentHashMap())
-    val visibleChunks: MutableMap<Vec2i, MutableMap<Int, ChunkMeshCollection>> = Collections.synchronizedMap(ConcurrentHashMap())
-    val queuedChunks: MutableSet<Vec2i> = Collections.synchronizedSet(mutableSetOf())
+    val allChunkSections: MutableMap<Vec2i, MutableMap<Int, ChunkMeshCollection>> = synchronizedMapOf()
+    val visibleChunks: MutableMap<Vec2i, MutableMap<Int, ChunkMeshCollection>> = synchronizedMapOf()
+    val queuedChunks: MutableSet<Vec2i> = synchronizedSetOf()
 
     private var allBlocks: Collection<BlockState>? = null
 
@@ -145,7 +145,7 @@ class WorldRenderer(
         })
 
         connection.registerEvent(CallbackEventInvoker.of<MultiBlockChangeEvent> {
-            val sectionHeights: MutableSet<Int> = mutableSetOf()
+            val sectionHeights: MutableSet<Int> = synchronizedSetOf()
             for ((key) in it.blocks) {
                 sectionHeights.add(key.sectionHeight)
             }
@@ -201,7 +201,7 @@ class WorldRenderer(
 
     private fun resolveBlockTextureIds(blocks: Collection<BlockState>): List<Texture> {
         val textures: MutableList<Texture> = mutableListOf()
-        val textureMap: MutableMap<String, Texture> = ConcurrentHashMap()
+        val textureMap: MutableMap<String, Texture> = synchronizedMapOf()
 
         for (block in blocks) {
             for (model in block.renderers) {
@@ -242,14 +242,14 @@ class WorldRenderer(
             }
         }
         queuedChunks.remove(chunkPosition)
-        allChunkSections[chunkPosition] = Collections.synchronizedMap(ConcurrentHashMap())
+        allChunkSections[chunkPosition] = synchronizedMapOf()
 
-        var currentChunks: MutableMap<Int, ChunkSection> = Collections.synchronizedMap(ConcurrentHashMap())
+        var currentChunks: MutableMap<Int, ChunkSection> = synchronizedMapOf()
         var currentIndex = 0
         for ((sectionHeight, section) in chunk.sections!!) {
             if (getSectionIndex(sectionHeight) != currentIndex) {
                 prepareChunkSections(chunkPosition, currentChunks)
-                currentChunks = Collections.synchronizedMap(ConcurrentHashMap())
+                currentChunks = synchronizedMapOf()
                 currentIndex = getSectionIndex(sectionHeight)
             }
             currentChunks[sectionHeight] = section
@@ -300,7 +300,7 @@ class WorldRenderer(
 
 
             renderWindow.renderQueue.add {
-                val sectionMap = allChunkSections.getOrPut(chunkPosition, { ConcurrentHashMap() })
+                val sectionMap = allChunkSections.getOrPut(chunkPosition) { synchronizedMapOf() }
 
                 sectionMap[index]?.let {
                     it.opaqueSectionArrayMesh.unload()
@@ -329,7 +329,7 @@ class WorldRenderer(
                 sectionMap[index] = meshCollection
 
                 if (renderWindow.inputHandler.camera.frustum.containsChunk(chunkPosition, lowestBlockHeight, highestBlockHeight)) {
-                    visibleChunks.getOrPut(chunkPosition, { ConcurrentHashMap() })[index] = meshCollection
+                    visibleChunks.getOrPut(chunkPosition) { synchronizedMapOf() }[index] = meshCollection
                 } else {
                     visibleChunks[chunkPosition]?.remove(index)
                 }
@@ -338,7 +338,7 @@ class WorldRenderer(
     }
 
     fun prepareChunkSection(chunkPosition: Vec2i, sectionHeight: Int) {
-        val sections: MutableMap<Int, ChunkSection> = Collections.synchronizedMap(ConcurrentHashMap())
+        val sections: MutableMap<Int, ChunkSection> = synchronizedMapOf()
         val chunk = world.getChunk(chunkPosition)!!
         val lowestSectionHeight = getSectionIndex(sectionHeight) * RenderConstants.CHUNK_SECTIONS_PER_MESH
         for (i in lowestSectionHeight until lowestSectionHeight + RenderConstants.CHUNK_SECTIONS_PER_MESH) {
@@ -381,7 +381,8 @@ class WorldRenderer(
     }
 
     private fun prepareWorld(world: World) {
-        for ((chunkLocation, chunk) in world.chunks) {
+        val chunkMap = world.chunks.toMap()
+        for ((chunkLocation, chunk) in chunkMap) {
             prepareChunk(chunkLocation, chunk)
         }
     }
@@ -393,8 +394,13 @@ class WorldRenderer(
 
     override fun onFrustumChange() {
         visibleChunks.clear()
-        for ((chunkLocation, indexMap) in allChunkSections) {
-            val visibleIndexMap: MutableMap<Int, ChunkMeshCollection> = Collections.synchronizedMap(ConcurrentHashMap())
+        val allChunkSections: Map<Vec2i, MutableMap<Int, ChunkMeshCollection>>
+        synchronized(this.allChunkSections) {
+            allChunkSections = this.allChunkSections.toMap()
+        }
+        for ((chunkLocation, rawIndexMap) in allChunkSections) {
+            val visibleIndexMap: MutableMap<Int, ChunkMeshCollection> = synchronizedMapOf()
+            val indexMap = rawIndexMap.toMap()
             for ((index, mesh) in indexMap) {
                 if (renderWindow.inputHandler.camera.frustum.containsChunk(chunkLocation, mesh.lowestBlockHeight, mesh.highestBlockHeight)) {
                     visibleIndexMap[index] = mesh
diff --git a/src/main/java/de/bixilon/minosoft/util/KUtil.kt b/src/main/java/de/bixilon/minosoft/util/KUtil.kt
index 141ddd49a..f49ffa82e 100644
--- a/src/main/java/de/bixilon/minosoft/util/KUtil.kt
+++ b/src/main/java/de/bixilon/minosoft/util/KUtil.kt
@@ -16,6 +16,7 @@ package de.bixilon.minosoft.util
 import de.bixilon.minosoft.data.mappings.ResourceLocation
 import de.bixilon.minosoft.util.enum.AliasableEnum
 import java.util.*
+import kotlin.Pair
 
 object KUtil {
 
@@ -53,4 +54,16 @@ object KUtil {
     fun String.asResourceLocation(): ResourceLocation {
         return ResourceLocation(this)
     }
+
+    fun <K, V> synchronizedMapOf(vararg pairs: Pair<K, V>): MutableMap<K, V> {
+        return Collections.synchronizedMap(mutableMapOf(*pairs))
+    }
+
+    fun <V> synchronizedSetOf(vararg values: V): MutableSet<V> {
+        return Collections.synchronizedSet(mutableSetOf(*values))
+    }
+
+    fun <V> synchronizedListOf(vararg values: V): MutableList<V> {
+        return Collections.synchronizedList(mutableListOf(*values))
+    }
 }
diff --git a/src/main/java/de/bixilon/minosoft/util/chunk/ChunkUtil.kt b/src/main/java/de/bixilon/minosoft/util/chunk/ChunkUtil.kt
index 9ce07b682..71305360f 100644
--- a/src/main/java/de/bixilon/minosoft/util/chunk/ChunkUtil.kt
+++ b/src/main/java/de/bixilon/minosoft/util/chunk/ChunkUtil.kt
@@ -24,8 +24,8 @@ import de.bixilon.minosoft.data.world.palette.Palette.Companion.choosePalette
 import de.bixilon.minosoft.protocol.protocol.PlayInByteBuffer
 import de.bixilon.minosoft.protocol.protocol.ProtocolDefinition
 import de.bixilon.minosoft.protocol.protocol.ProtocolVersions.*
+import de.bixilon.minosoft.util.KUtil.synchronizedMapOf
 import java.util.*
-import java.util.concurrent.ConcurrentHashMap
 
 
 object ChunkUtil {
@@ -59,7 +59,7 @@ object ChunkUtil {
 
         // parse data
         var arrayPosition = 0
-        val sectionMap: MutableMap<Int, ChunkSection> = Collections.synchronizedMap(ConcurrentHashMap())
+        val sectionMap: MutableMap<Int, ChunkSection> = synchronizedMapOf()
         for ((sectionIndex, sectionHeight) in (dimension.lowestSection until dimension.highestSection).withIndex()) {
             if (!sectionBitMask[sectionIndex]) {
                 continue
@@ -125,7 +125,7 @@ object ChunkUtil {
         }
 
         var arrayPos = 0
-        val sectionMap: MutableMap<Int, ChunkSection> = Collections.synchronizedMap(ConcurrentHashMap())
+        val sectionMap: MutableMap<Int, ChunkSection> = synchronizedMapOf()
         for ((sectionIndex, sectionHeight) in (dimension.lowestSection until dimension.highestSection).withIndex()) { // max sections per chunks in chunk column
             if (!sectionBitMask[sectionIndex]) {
                 continue
@@ -144,7 +144,7 @@ object ChunkUtil {
 
     fun readPaletteChunk(buffer: PlayInByteBuffer, dimension: Dimension, sectionBitMask: BitSet, isFullChunk: Boolean, containsSkyLight: Boolean = false): ChunkData {
         val chunkData = ChunkData()
-        val sectionMap: MutableMap<Int, ChunkSection> = Collections.synchronizedMap(ConcurrentHashMap())
+        val sectionMap: MutableMap<Int, ChunkSection> = synchronizedMapOf()
 
         for ((sectionIndex, sectionHeight) in (dimension.lowestSection until sectionBitMask.length()).withIndex()) { // max sections per chunks in chunk column
             if (!sectionBitMask[sectionIndex]) {