diff --git a/activemq-core/src/main/java/org/apache/activemq/store/jdbc/adapter/DefaultJDBCAdapter.java b/activemq-core/src/main/java/org/apache/activemq/store/jdbc/adapter/DefaultJDBCAdapter.java
index 8df17e716a..9b0b93597a 100755
--- a/activemq-core/src/main/java/org/apache/activemq/store/jdbc/adapter/DefaultJDBCAdapter.java
+++ b/activemq-core/src/main/java/org/apache/activemq/store/jdbc/adapter/DefaultJDBCAdapter.java
@@ -22,11 +22,13 @@ import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Set;
 import java.util.TreeSet;
+
 import org.apache.activemq.command.ActiveMQDestination;
 import org.apache.activemq.command.MessageId;
 import org.apache.activemq.command.SubscriptionInfo;
@@ -55,7 +57,7 @@ public class DefaultJDBCAdapter implements JDBCAdapter {
     private static final Log LOG = LogFactory.getLog(DefaultJDBCAdapter.class);
     protected Statements statements;
     protected boolean batchStatments = true;
-    private Set<Long> lastRecoveredMessagesIds = new TreeSet<Long>();
+    private Set<Long> lastRecoveredMessagesIds = Collections.synchronizedSet(new TreeSet<Long>());
 
     protected void setBinaryData(PreparedStatement s, int index, byte data[]) throws SQLException {
         s.setBytes(index, data);