diff --git a/src/main/java/net/minestom/server/thread/MinestomThread.java b/src/main/java/net/minestom/server/thread/MinestomThread.java
index c293fd622..26e718d01 100644
--- a/src/main/java/net/minestom/server/thread/MinestomThread.java
+++ b/src/main/java/net/minestom/server/thread/MinestomThread.java
@@ -33,7 +33,7 @@ public class MinestomThread extends Thread {
         final int requiredLength = index + 1;
         if (array.length < requiredLength) {
             Object[] temp = new Object[requiredLength];
-            System.arraycopy(array, 0, temp, 0, index);
+            System.arraycopy(array, 0, temp, 0, array.length);
             array = temp;
             this.locals = array;
         }
diff --git a/src/test/java/thread/LocalThreadCache.java b/src/test/java/thread/LocalThreadCache.java
index 3a4f67b95..14e1217c5 100644
--- a/src/test/java/thread/LocalThreadCache.java
+++ b/src/test/java/thread/LocalThreadCache.java
@@ -18,16 +18,16 @@ public class LocalThreadCache {
             public void run() {
                 final int dummy = -1;
 
-                var value = localCache(0, () -> 5);
+                var value = localCache(1, () -> 7);
+                assertEquals(7, value);
+
+                value = localCache(0, () -> 5);
                 assertEquals(5, value);
+                assertEquals(7, localCache(1, () -> dummy));
 
                 value = localCache(0, () -> dummy);
                 assertEquals(5, value);
 
-                value = localCache(1, () -> 7);
-                assertEquals(7, value);
-                assertEquals(5, localCache(0, () -> dummy));
-
                 value = localCache(2, () -> 5);
                 assertEquals(5, value);
                 assertEquals(7, localCache(1, () -> dummy));