diff --git a/activemq-kahadb-store/src/main/java/org/apache/activemq/store/kahadb/MessageDatabase.java b/activemq-kahadb-store/src/main/java/org/apache/activemq/store/kahadb/MessageDatabase.java
index ea53ad0d10..0611be77c1 100644
--- a/activemq-kahadb-store/src/main/java/org/apache/activemq/store/kahadb/MessageDatabase.java
+++ b/activemq-kahadb-store/src/main/java/org/apache/activemq/store/kahadb/MessageDatabase.java
@@ -1524,7 +1524,7 @@ public abstract class MessageDatabase extends ServiceSupport implements BrokerSe
                 decrementAndSubSizeToStoreStat(command.getDestination(), previousKeys.location.getSize());
 
                 //update all the subscription metrics
-                if (enableSubscriptionStatistics && location.getSize() != previousKeys.location.getSize()) {
+                if (enableSubscriptionStatistics && sd.ackPositions != null && location.getSize() != previousKeys.location.getSize()) {
                     Iterator<Entry<String, SequenceSet>> iter = sd.ackPositions.iterator(tx);
                     while (iter.hasNext()) {
                         Entry<String, SequenceSet> e = iter.next();
@@ -2970,33 +2970,38 @@ public abstract class MessageDatabase extends ServiceSupport implements BrokerSe
         return sd.subscriptionAcks.get(tx, subscriptionKey);
     }
 
-    public long getStoredMessageCount(Transaction tx, StoredDestination sd, String subscriptionKey) throws IOException {
-        SequenceSet messageSequences = sd.ackPositions.get(tx, subscriptionKey);
-        if (messageSequences != null) {
-            long result = messageSequences.rangeSize();
-            // if there's anything in the range the last value is always the nextMessage marker, so remove 1.
-            return result > 0 ? result - 1 : 0;
+    protected long getStoredMessageCount(Transaction tx, StoredDestination sd, String subscriptionKey) throws IOException {
+        if (sd.ackPositions != null) {
+            SequenceSet messageSequences = sd.ackPositions.get(tx, subscriptionKey);
+            if (messageSequences != null) {
+                long result = messageSequences.rangeSize();
+                // if there's anything in the range the last value is always the nextMessage marker, so remove 1.
+                return result > 0 ? result - 1 : 0;
+            }
         }
 
         return 0;
     }
 
-    public long getStoredMessageSize(Transaction tx, StoredDestination sd, String subscriptionKey) throws IOException {
-        //grab the messages attached to this subscription
-        SequenceSet messageSequences = sd.ackPositions.get(tx, subscriptionKey);
-
+    protected long getStoredMessageSize(Transaction tx, StoredDestination sd, String subscriptionKey) throws IOException {
         long locationSize = 0;
-        if (messageSequences != null) {
-            Sequence head = messageSequences.getHead();
-            if (head != null) {
-                //get an iterator over the order index starting at the first unacked message
-                //and go over each message to add up the size
-                Iterator<Entry<Long, MessageKeys>> iterator = sd.orderIndex.iterator(tx,
-                        new MessageOrderCursor(head.getFirst()));
 
-                while (iterator.hasNext()) {
-                    Entry<Long, MessageKeys> entry = iterator.next();
-                    locationSize += entry.getValue().location.getSize();
+        if (sd.ackPositions != null) {
+            //grab the messages attached to this subscription
+            SequenceSet messageSequences = sd.ackPositions.get(tx, subscriptionKey);
+
+            if (messageSequences != null) {
+                Sequence head = messageSequences.getHead();
+                if (head != null) {
+                    //get an iterator over the order index starting at the first unacked message
+                    //and go over each message to add up the size
+                    Iterator<Entry<Long, MessageKeys>> iterator = sd.orderIndex.iterator(tx,
+                            new MessageOrderCursor(head.getFirst()));
+
+                    while (iterator.hasNext()) {
+                        Entry<Long, MessageKeys> entry = iterator.next();
+                        locationSize += entry.getValue().location.getSize();
+                    }
                 }
             }
         }
diff --git a/activemq-kahadb-store/src/test/java/org/apache/activemq/store/kahadb/MessageDatabaseSizeTest.java b/activemq-kahadb-store/src/test/java/org/apache/activemq/store/kahadb/MessageDatabaseSizeTest.java
index 357dc5fd54..4deb1e07b9 100644
--- a/activemq-kahadb-store/src/test/java/org/apache/activemq/store/kahadb/MessageDatabaseSizeTest.java
+++ b/activemq-kahadb-store/src/test/java/org/apache/activemq/store/kahadb/MessageDatabaseSizeTest.java
@@ -17,9 +17,12 @@
 package org.apache.activemq.store.kahadb;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
 
 import java.io.File;
 import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collection;
 
 import org.apache.activemq.broker.BrokerService;
 import org.apache.activemq.command.ActiveMQQueue;
@@ -36,13 +39,27 @@ import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameters;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+@RunWith(Parameterized.class)
 public class MessageDatabaseSizeTest {
 
     private static final Logger LOG = LoggerFactory.getLogger(MessageDatabaseSizeTest.class);
 
+    @Parameters(name = "subStatsEnabled={0}")
+    public static Collection<Object[]> data() {
+        return Arrays.asList(new Object[][] {
+                // Subscription stats on
+                {true},
+                // Subscription stats off
+                {false}
+        });
+    }
+
     @Rule
     public TemporaryFolder dataDir = new TemporaryFolder(new File("target"));
     private final String payload = new String(new byte[1024]);
@@ -50,6 +67,13 @@ public class MessageDatabaseSizeTest {
     private BrokerService broker = null;
     private final ActiveMQQueue destination = new ActiveMQQueue("Test");
     private KahaDBPersistenceAdapter adapter;
+    private boolean subStatsEnabled;
+
+    public MessageDatabaseSizeTest(boolean subStatsEnabled) {
+        super();
+        this.subStatsEnabled = subStatsEnabled;
+    }
+
 
     protected void startBroker() throws Exception {
         broker = new BrokerService();
@@ -58,6 +82,7 @@ public class MessageDatabaseSizeTest {
         broker.setUseJmx(true);
         broker.setDataDirectory(dataDir.getRoot().getAbsolutePath());
         adapter = (KahaDBPersistenceAdapter) broker.getPersistenceAdapter();
+        adapter.setEnableSubscriptionStatistics(subStatsEnabled);
         broker.start();
         LOG.info("Starting broker..");
     }
@@ -101,6 +126,22 @@ public class MessageDatabaseSizeTest {
         assertEquals(existingSize, messageStore.getMessageSize());
     }
 
+    @Test
+    public void testUpdateMessageSameLocationDifferentSize() throws Exception {
+        final KahaDBStore store = adapter.getStore();
+        MessageId messageId = new MessageId("111:222:333");
+        ActiveMQTextMessage textMessage = getMessage(new MessageId("111:222:333"));
+
+        //Add a single message and update once so we can compare the size consistently
+        MessageStore messageStore = store.createQueueMessageStore(destination);
+        messageStore.addMessage(broker.getAdminConnectionContext(), textMessage);
+        textMessage.setText("new size of message");
+        messageStore.updateMessage(textMessage);
+
+        assertNotNull(findMessageLocation(messageId.toString(), store.convert(destination)));
+
+    }
+
     /**
      * Test that when updating an existing message to a different location in the
      * journal that the index size doesn't change