diff --git a/pom.xml b/pom.xml
index e3e9828..78da0ec 100644
--- a/pom.xml
+++ b/pom.xml
@@ -67,7 +67,7 @@
         <!-- Do not change unless you want different name for local builds. -->
         <build.number>-LOCAL</build.number>
         <!-- This allows to change between versions. -->
-        <build.version>2.21.2</build.version>
+        <build.version>2.21.3</build.version>
         <sonar.projectKey>BentoBoxWorld_Level</sonar.projectKey>
         <sonar.organization>bentobox-world</sonar.organization>
         <sonar.host.url>https://sonarcloud.io</sonar.host.url>
diff --git a/src/main/java/world/bentobox/level/calculators/IslandLevelCalculator.java b/src/main/java/world/bentobox/level/calculators/IslandLevelCalculator.java
index 78d1470..639bcdc 100644
--- a/src/main/java/world/bentobox/level/calculators/IslandLevelCalculator.java
+++ b/src/main/java/world/bentobox/level/calculators/IslandLevelCalculator.java
@@ -56,6 +56,7 @@
 import world.bentobox.level.config.BlockConfig;
 
 public class IslandLevelCalculator {
+    private final UUID calcId = UUID.randomUUID();  // ID for hashing
     private static final String LINE_BREAK = "==================================";
     public static final long MAX_AMOUNT = 10000000;
     private static final int CHUNKS_TO_SCAN = 100;
@@ -791,4 +792,16 @@ private CompletableFuture<Void> handleStackedBlocks() {
 
     }
 
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (!(o instanceof IslandLevelCalculator)) return false;
+        IslandLevelCalculator that = (IslandLevelCalculator) o;
+        return calcId.equals(that.calcId);
+    }
+
+    @Override
+    public int hashCode() {
+        return calcId.hashCode();
+    }
 }