diff --git a/src/main/java/world/bentobox/challenges/ChallengesManager.java b/src/main/java/world/bentobox/challenges/ChallengesManager.java
index 3782c83..a073dbd 100644
--- a/src/main/java/world/bentobox/challenges/ChallengesManager.java
+++ b/src/main/java/world/bentobox/challenges/ChallengesManager.java
@@ -435,7 +435,7 @@ public class ChallengesManager
 
                 Iterator<LogEntry> entryIterator = cachedData.getHistory().iterator();
 
-                while (this.shouldBeRemoved(entryIterator.next(), survivalTime))
+                while (entryIterator.hasNext() && this.shouldBeRemoved(entryIterator.next(), survivalTime))
                 {
                     entryIterator.remove();
                 }