diff --git a/src/main/java/net/minestom/server/instance/Chunk.java b/src/main/java/net/minestom/server/instance/Chunk.java
index e2327e266..91b046004 100644
--- a/src/main/java/net/minestom/server/instance/Chunk.java
+++ b/src/main/java/net/minestom/server/instance/Chunk.java
@@ -459,7 +459,7 @@ public abstract class Chunk implements Viewable, DataContainer {
      *
      * @param player the player
      */
-    protected void sendChunk(@NotNull Player player) {
+    protected synchronized void sendChunk(@NotNull Player player) {
         // Only send loaded chunk
         if (!isLoaded())
             return;
@@ -503,7 +503,7 @@ public abstract class Chunk implements Viewable, DataContainer {
      *
      * @param player the player to update the chunk to
      */
-    public void sendChunkUpdate(@NotNull Player player) {
+    public synchronized void sendChunkUpdate(@NotNull Player player) {
         final PlayerConnection playerConnection = player.getPlayerConnection();
         playerConnection.sendPacket(getFreshFullDataPacket());
     }
@@ -511,7 +511,7 @@ public abstract class Chunk implements Viewable, DataContainer {
     /**
      * Sends a full {@link ChunkDataPacket} to all chunk viewers.
      */
-    public void sendChunkUpdate() {
+    public synchronized void sendChunkUpdate() {
         final Set<Player> chunkViewers = getViewers();
         if (!chunkViewers.isEmpty()) {
             chunkViewers.forEach(player -> {
@@ -528,7 +528,7 @@ public abstract class Chunk implements Viewable, DataContainer {
      * @param player  the player to send the packet to
      * @throws IllegalArgumentException if {@code section} is not a valid section
      */
-    public void sendChunkSectionUpdate(int section, @NotNull Player player) {
+    public synchronized void sendChunkSectionUpdate(int section, @NotNull Player player) {
         if (!PlayerUtils.isNettyClient(player))
             return;
         Check.argCondition(!MathUtils.isBetween(section, 0, CHUNK_SECTION_COUNT),
diff --git a/src/main/java/net/minestom/server/instance/batch/ChunkBatch.java b/src/main/java/net/minestom/server/instance/batch/ChunkBatch.java
index 40440a5e7..1e7c61567 100644
--- a/src/main/java/net/minestom/server/instance/batch/ChunkBatch.java
+++ b/src/main/java/net/minestom/server/instance/batch/ChunkBatch.java
@@ -116,21 +116,23 @@ public class ChunkBatch implements InstanceBatch {
      */
     public void flushChunkGenerator(@NotNull ChunkGenerator chunkGenerator, @Nullable ChunkCallback callback) {
         BLOCK_BATCH_POOL.execute(() -> {
-            final List<ChunkPopulator> populators = chunkGenerator.getPopulators();
-            final boolean hasPopulator = populators != null && !populators.isEmpty();
+            synchronized (chunk) {
+                final List<ChunkPopulator> populators = chunkGenerator.getPopulators();
+                final boolean hasPopulator = populators != null && !populators.isEmpty();
 
-            chunkGenerator.generateChunkData(this, chunk.getChunkX(), chunk.getChunkZ());
+                chunkGenerator.generateChunkData(this, chunk.getChunkX(), chunk.getChunkZ());
 
-            if (hasPopulator) {
-                for (ChunkPopulator chunkPopulator : populators) {
-                    chunkPopulator.populateChunk(this, chunk);
+                if (hasPopulator) {
+                    for (ChunkPopulator chunkPopulator : populators) {
+                        chunkPopulator.populateChunk(this, chunk);
+                    }
                 }
-            }
 
-            // Safe callback
-            instance.scheduleNextTick(inst -> {
-                OptionalCallback.execute(callback, chunk);
-            });
+                // Safe callback
+                instance.scheduleNextTick(inst -> {
+                    OptionalCallback.execute(callback, chunk);
+                });
+            }
         });
     }
 
diff --git a/src/main/java/net/minestom/server/utils/cache/TemporaryCache.java b/src/main/java/net/minestom/server/utils/cache/TemporaryCache.java
index 07ea8a51f..960626a20 100644
--- a/src/main/java/net/minestom/server/utils/cache/TemporaryCache.java
+++ b/src/main/java/net/minestom/server/utils/cache/TemporaryCache.java
@@ -23,7 +23,7 @@ public class TemporaryCache<T> {
     // Identifier = time
     protected ConcurrentHashMap<UUID, Long> cacheTime = new ConcurrentHashMap<>();
 
-    private long keepTime;
+    private final long keepTime;
 
     /**
      * Creates a new temporary cache.
@@ -42,13 +42,13 @@ public class TemporaryCache<T> {
     }
 
     /**
-     * Caches an object
+     * Caches an object.
      *
      * @param identifier the object identifier
      * @param value      the object to cache
      * @param time       the current time in milliseconds
      */
-    public synchronized void cacheObject(@NotNull UUID identifier, T value, long time) {
+    public void cacheObject(@NotNull UUID identifier, T value, long time) {
         this.cache.put(identifier, value);
         this.cacheTime.put(identifier, time);
     }