diff --git a/p2p/src/main/java/haveno/network/p2p/storage/P2PDataStorage.java b/p2p/src/main/java/haveno/network/p2p/storage/P2PDataStorage.java
index 40be21ef..05170971 100644
--- a/p2p/src/main/java/haveno/network/p2p/storage/P2PDataStorage.java
+++ b/p2p/src/main/java/haveno/network/p2p/storage/P2PDataStorage.java
@@ -187,7 +187,9 @@ public class P2PDataStorage implements MessageListener, ConnectionListener, Pers
     @Override
     public void readPersisted(Runnable completeHandler) {
         persistenceManager.readPersisted(persisted -> {
-            sequenceNumberMap.setMap(getPurgedSequenceNumberMap(persisted.getMap()));
+            synchronized (persisted.getMap()) {
+                sequenceNumberMap.setMap(getPurgedSequenceNumberMap(persisted.getMap()));
+            }
             completeHandler.run();
         },
                 completeHandler);
@@ -198,7 +200,9 @@ public class P2PDataStorage implements MessageListener, ConnectionListener, Pers
     public void readPersistedSync() {
         SequenceNumberMap persisted = persistenceManager.getPersisted();
         if (persisted != null) {
-            sequenceNumberMap.setMap(getPurgedSequenceNumberMap(persisted.getMap()));
+            synchronized (persisted.getMap()) {
+                sequenceNumberMap.setMap(getPurgedSequenceNumberMap(persisted.getMap()));
+            }
         }
     }
 
@@ -641,9 +645,11 @@ public class P2PDataStorage implements MessageListener, ConnectionListener, Pers
             }
             removeFromMapAndDataStore(toRemoveList);
 
-            if (sequenceNumberMap.size() > this.maxSequenceNumberMapSizeBeforePurge) {
-                sequenceNumberMap.setMap(getPurgedSequenceNumberMap(sequenceNumberMap.getMap()));
-                requestPersistence();
+            synchronized (sequenceNumberMap.getMap()) {
+                if (sequenceNumberMap.size() > this.maxSequenceNumberMapSizeBeforePurge) {
+                    sequenceNumberMap.setMap(getPurgedSequenceNumberMap(sequenceNumberMap.getMap()));
+                    requestPersistence();
+                }
             }
         }
     }
diff --git a/p2p/src/main/java/haveno/network/p2p/storage/persistence/SequenceNumberMap.java b/p2p/src/main/java/haveno/network/p2p/storage/persistence/SequenceNumberMap.java
index f774c4c3..43cf2c1e 100644
--- a/p2p/src/main/java/haveno/network/p2p/storage/persistence/SequenceNumberMap.java
+++ b/p2p/src/main/java/haveno/network/p2p/storage/persistence/SequenceNumberMap.java
@@ -19,8 +19,6 @@ package haveno.network.p2p.storage.persistence;
 
 import haveno.common.proto.persistable.PersistableEnvelope;
 import haveno.network.p2p.storage.P2PDataStorage;
-import lombok.Getter;
-import lombok.Setter;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -33,8 +31,6 @@ import java.util.stream.Collectors;
  * Hence this Persistable class.
  */
 public class SequenceNumberMap implements PersistableEnvelope {
-    @Getter
-    @Setter
     private Map<P2PDataStorage.ByteArray, P2PDataStorage.MapValue> map = new ConcurrentHashMap<>();
 
     public SequenceNumberMap() {
@@ -46,20 +42,24 @@ public class SequenceNumberMap implements PersistableEnvelope {
     ///////////////////////////////////////////////////////////////////////////////////////////
 
     private SequenceNumberMap(Map<P2PDataStorage.ByteArray, P2PDataStorage.MapValue> map) {
-        this.map.putAll(map);
+        synchronized (this.map) {
+            this.map.putAll(map);
+        }
     }
 
     @Override
     public protobuf.PersistableEnvelope toProtoMessage() {
-        return protobuf.PersistableEnvelope.newBuilder()
-                .setSequenceNumberMap(protobuf.SequenceNumberMap.newBuilder()
-                        .addAllSequenceNumberEntries(map.entrySet().stream()
-                                .map(entry -> protobuf.SequenceNumberEntry.newBuilder()
-                                        .setBytes(entry.getKey().toProtoMessage())
-                                        .setMapValue(entry.getValue().toProtoMessage())
-                                        .build())
-                                .collect(Collectors.toList())))
-                .build();
+        synchronized (map) {
+            return protobuf.PersistableEnvelope.newBuilder()
+                    .setSequenceNumberMap(protobuf.SequenceNumberMap.newBuilder()
+                            .addAllSequenceNumberEntries(map.entrySet().stream()
+                                    .map(entry -> protobuf.SequenceNumberEntry.newBuilder()
+                                            .setBytes(entry.getKey().toProtoMessage())
+                                            .setMapValue(entry.getValue().toProtoMessage())
+                                            .build())
+                                    .collect(Collectors.toList())))
+                    .build();
+        }
     }
 
     public static SequenceNumberMap fromProto(protobuf.SequenceNumberMap proto) {
@@ -74,20 +74,40 @@ public class SequenceNumberMap implements PersistableEnvelope {
     // API
     ///////////////////////////////////////////////////////////////////////////////////////////
 
+    public Map<P2PDataStorage.ByteArray, P2PDataStorage.MapValue> getMap() {
+        synchronized (map) {
+            return map;
+        }
+    }
+
+    public void setMap(Map<P2PDataStorage.ByteArray, P2PDataStorage.MapValue> map) {
+        synchronized (this.map) {
+            this.map = map;
+        }
+    }
+
     // Delegates
     public int size() {
-        return map.size();
+        synchronized (map) {
+            return map.size();
+        }
     }
 
     public boolean containsKey(P2PDataStorage.ByteArray key) {
-        return map.containsKey(key);
+        synchronized (map) {
+            return map.containsKey(key);
+        }
     }
 
     public P2PDataStorage.MapValue get(P2PDataStorage.ByteArray key) {
-        return map.get(key);
+        synchronized (map) {
+            return map.get(key);
+        }
     }
 
     public void put(P2PDataStorage.ByteArray key, P2PDataStorage.MapValue value) {
-        map.put(key, value);
+        synchronized (map) {
+            map.put(key, value);
+        }
     }
 }