diff --git a/pom.xml b/pom.xml
index 7f4425e..5adb789 100644
--- a/pom.xml
+++ b/pom.xml
@@ -6,7 +6,7 @@
 
 	<groupId>world.bentobox</groupId>
 	<artifactId>challenges</artifactId>
-	<version>0.5.0</version>
+	<version>0.5.1</version>
 
 	<name>Challenges</name>
 	<description>Challenges is an add-on for BentoBox, an expandable Minecraft Bukkit plugin for island-type games like SkyBlock, AcidIsland or CaveBlock.</description>
diff --git a/src/main/java/world/bentobox/challenges/panel/TryToComplete.java b/src/main/java/world/bentobox/challenges/panel/TryToComplete.java
index fcabbc4..934201c 100644
--- a/src/main/java/world/bentobox/challenges/panel/TryToComplete.java
+++ b/src/main/java/world/bentobox/challenges/panel/TryToComplete.java
@@ -210,7 +210,9 @@ public class TryToComplete
             // Item rewards
             for (ItemStack reward : this.challenge.getRewardItems())
             {
-                this.user.getInventory().addItem(reward).forEach((k, v) ->
+                // Clone is necessary because otherwise it will chane reward itemstack
+                // amount.
+                this.user.getInventory().addItem(reward.clone()).forEach((k, v) ->
                     this.user.getWorld().dropItem(this.user.getLocation(), v));
             }
 
@@ -247,7 +249,9 @@ public class TryToComplete
             // Item Repeat Rewards
             for (ItemStack reward : this.challenge.getRepeatItemReward())
             {
-                this.user.getInventory().addItem(reward).forEach((k, v) ->
+                // Clone is necessary because otherwise it will chane reward itemstack
+                // amount.
+                this.user.getInventory().addItem(reward.clone()).forEach((k, v) ->
                     this.user.getWorld().dropItem(this.user.getLocation(), v));
             }
 
@@ -280,7 +284,9 @@ public class TryToComplete
                     // Item rewards
                     for (ItemStack reward : level.getRewardItems())
                     {
-                        this.user.getInventory().addItem(reward).forEach((k, v) ->
+                        // Clone is necessary because otherwise it will chane reward itemstack
+                        // amount.
+                        this.user.getInventory().addItem(reward.clone()).forEach((k, v) ->
                             this.user.getWorld().dropItem(this.user.getLocation(), v));
                     }