diff --git a/core/src/main/java/org/bitcoinj/wallet/WalletProtobufSerializer.java b/core/src/main/java/org/bitcoinj/wallet/WalletProtobufSerializer.java
index 324863b6..cbe9a58c 100644
--- a/core/src/main/java/org/bitcoinj/wallet/WalletProtobufSerializer.java
+++ b/core/src/main/java/org/bitcoinj/wallet/WalletProtobufSerializer.java
@@ -31,6 +31,7 @@ import org.bitcoinj.wallet.Protos.Wallet.EncryptionType;
 import com.google.common.collect.Lists;
 import com.google.protobuf.ByteString;
 import com.google.protobuf.CodedInputStream;
+import com.google.protobuf.CodedOutputStream;
 import com.google.protobuf.TextFormat;
 import com.google.protobuf.WireFormat;
 
@@ -78,6 +79,7 @@ public class WalletProtobufSerializer {
     protected Map<ByteString, Transaction> txMap;
 
     private boolean requireMandatoryExtensions = true;
+    private int walletWriteBufferSize = CodedOutputStream.DEFAULT_BUFFER_SIZE;
 
     public interface WalletFactory {
         Wallet create(NetworkParameters params, KeyChainGroup keyChainGroup);
@@ -114,6 +116,14 @@ public class WalletProtobufSerializer {
         requireMandatoryExtensions = value;
     }
 
+    /**
+     * Change buffer size for writing wallet to output stream. Default is {@link com.google.protobuf.CodedOutputStream.DEFAULT_BUFFER_SIZE}
+     * @param walletWriteBufferSize - buffer size in bytes
+     */
+    public void setWalletWriteBufferSize(int walletWriteBufferSize) {
+        this.walletWriteBufferSize = walletWriteBufferSize;
+    }
+
     /**
      * Formats the given wallet (transactions and keys) to the given output stream in protocol buffer format.<p>
      *
@@ -121,7 +131,9 @@ public class WalletProtobufSerializer {
      */
     public void writeWallet(Wallet wallet, OutputStream output) throws IOException {
         Protos.Wallet walletProto = walletToProto(wallet);
-        walletProto.writeTo(output);
+        final CodedOutputStream codedOutput = CodedOutputStream.newInstance(output, this.walletWriteBufferSize);
+        walletProto.writeTo(codedOutput);
+        codedOutput.flush();
     }
 
     /**