diff --git a/pulsar-broker/src/main/java/org/apache/pulsar/broker/service/persistent/PersistentSubscription.java b/pulsar-broker/src/main/java/org/apache/pulsar/broker/service/persistent/PersistentSubscription.java
index 86251691496bd..ddcd4614126b5 100644
--- a/pulsar-broker/src/main/java/org/apache/pulsar/broker/service/persistent/PersistentSubscription.java
+++ b/pulsar-broker/src/main/java/org/apache/pulsar/broker/service/persistent/PersistentSubscription.java
@@ -1046,8 +1046,9 @@ public List<Consumer> getConsumers() {
 
     @Override
     public boolean expireMessages(int messageTTLInSeconds) {
-        if ((getNumberOfEntriesInBacklog(false) == 0) || (dispatcher != null && dispatcher.isConsumerConnected()
-                && getNumberOfEntriesInBacklog(false) < MINIMUM_BACKLOG_FOR_EXPIRY_CHECK
+        long backlog = getNumberOfEntriesInBacklog(false);
+        if (backlog == 0 || (dispatcher != null && dispatcher.isConsumerConnected()
+                && backlog < MINIMUM_BACKLOG_FOR_EXPIRY_CHECK
                 && !topic.isOldestMessageExpired(cursor, messageTTLInSeconds))) {
             // don't do anything for almost caught-up connected subscriptions
             return false;