diff --git a/src/main/java/com/sparrowwallet/drongo/wallet/Wallet.java b/src/main/java/com/sparrowwallet/drongo/wallet/Wallet.java
index d65ab46..26c6f92 100644
--- a/src/main/java/com/sparrowwallet/drongo/wallet/Wallet.java
+++ b/src/main/java/com/sparrowwallet/drongo/wallet/Wallet.java
@@ -75,12 +75,18 @@ public class Wallet {
         return keystores;
     }
 
-    private Set<WalletNode> getPurposeNodes() {
-        return purposeNodes;
+    public Map<Sha256Hash, BlockTransaction> getTransactions() {
+        return Collections.unmodifiableMap(transactions);
     }
 
-    public Map<Sha256Hash, BlockTransaction> getTransactions() {
-        return transactions;
+    public synchronized void updateTransactions(Map<Sha256Hash, BlockTransaction> updatedTransactions) {
+        for(BlockTransaction blockTx : updatedTransactions.values()) {
+            Optional<String> optionalLabel = transactions.values().stream().filter(oldBlTx -> oldBlTx.getHash().equals(blockTx.getHash())).map(BlockTransaction::getLabel).filter(Objects::nonNull).findFirst();
+            optionalLabel.ifPresent(blockTx::setLabel);
+        }
+
+        transactions.clear();
+        transactions.putAll(updatedTransactions);
     }
 
     public Integer getStoredBlockHeight() {
@@ -91,7 +97,7 @@ public class Wallet {
         this.storedBlockHeight = storedBlockHeight;
     }
 
-    public WalletNode getNode(KeyPurpose keyPurpose) {
+    public synchronized WalletNode getNode(KeyPurpose keyPurpose) {
         WalletNode purposeNode;
         Optional<WalletNode> optionalPurposeNode = purposeNodes.stream().filter(node -> node.getKeyPurpose().equals(keyPurpose)).findFirst();
         if(optionalPurposeNode.isEmpty()) {
@@ -310,10 +316,10 @@ public class Wallet {
             copy.getKeystores().add(keystore.copy());
         }
         for(WalletNode node : purposeNodes) {
-            copy.getPurposeNodes().add(node.copy());
+            copy.purposeNodes.add(node.copy());
         }
         for(Sha256Hash hash : transactions.keySet()) {
-            copy.getTransactions().put(hash, transactions.get(hash));
+            copy.transactions.put(hash, transactions.get(hash));
         }
 
         return copy;
diff --git a/src/main/java/com/sparrowwallet/drongo/wallet/WalletNode.java b/src/main/java/com/sparrowwallet/drongo/wallet/WalletNode.java
index e74da7a..21941d6 100644
--- a/src/main/java/com/sparrowwallet/drongo/wallet/WalletNode.java
+++ b/src/main/java/com/sparrowwallet/drongo/wallet/WalletNode.java
@@ -87,7 +87,7 @@ public class WalletNode implements Comparable<WalletNode> {
     }
 
     public Set<WalletNode> getChildren() {
-        return children;
+        return children == null ? null : Collections.unmodifiableSet(children);
     }
 
     public void setChildren(Set<WalletNode> children) {
@@ -95,13 +95,23 @@ public class WalletNode implements Comparable<WalletNode> {
     }
 
     public Set<BlockTransactionHashIndex> getTransactionOutputs() {
-        return transactionOutputs;
+        return transactionOutputs == null ? null : Collections.unmodifiableSet(transactionOutputs);
     }
 
     public void setTransactionOutputs(Set<BlockTransactionHashIndex> transactionOutputs) {
         this.transactionOutputs = transactionOutputs;
     }
 
+    public synchronized void updateTransactionOutputs(Set<BlockTransactionHashIndex> updatedOutputs) {
+        for(BlockTransactionHashIndex txo : updatedOutputs) {
+            Optional<String> optionalLabel = transactionOutputs.stream().filter(oldTxo -> oldTxo.getHash().equals(txo.getHash()) && oldTxo.getIndex() == txo.getIndex()).map(BlockTransactionHash::getLabel).filter(Objects::nonNull).findFirst();
+            optionalLabel.ifPresent(txo::setLabel);
+        }
+
+        transactionOutputs.clear();
+        transactionOutputs.addAll(updatedOutputs);
+    }
+
     public Set<BlockTransactionHashIndex> getUnspentTransactionOutputs() {
         Set<BlockTransactionHashIndex> unspentTXOs = new TreeSet<>(transactionOutputs);
         return unspentTXOs.stream().filter(txo -> !txo.isSpent()).collect(Collectors.toCollection(HashSet::new));
@@ -116,10 +126,10 @@ public class WalletNode implements Comparable<WalletNode> {
         return value;
     }
 
-    public void fillToIndex(int index) {
+    public synchronized void fillToIndex(int index) {
         for(int i = 0; i <= index; i++) {
             WalletNode node = new WalletNode(getKeyPurpose(), i);
-            getChildren().add(node);
+            children.add(node);
         }
     }
 
@@ -172,7 +182,7 @@ public class WalletNode implements Comparable<WalletNode> {
         return 0;
     }
 
-    public void clearHistory() {
+    public synchronized void clearHistory() {
         transactionOutputs.clear();
         for(WalletNode childNode : getChildren()) {
             childNode.clearHistory();
@@ -184,11 +194,11 @@ public class WalletNode implements Comparable<WalletNode> {
         copy.setLabel(label);
 
         for(WalletNode child : getChildren()) {
-            copy.getChildren().add(child.copy());
+            copy.children.add(child.copy());
         }
 
         for(BlockTransactionHashIndex txo : getTransactionOutputs()) {
-            copy.getTransactionOutputs().add(txo.copy());
+            copy.transactionOutputs.add(txo.copy());
         }
 
         return copy;