diff --git a/src/qt/sendcoinsentry.cpp b/src/qt/sendcoinsentry.cpp
index 4697423868..26bd96b33c 100644
--- a/src/qt/sendcoinsentry.cpp
+++ b/src/qt/sendcoinsentry.cpp
@@ -11,6 +11,7 @@
 #include "optionsmodel.h"
 #include "platformstyle.h"
 #include "walletmodel.h"
+#include "../spark/sparkwallet.h"
 #include "../wallet/wallet.h"
 
 #include <QApplication>
@@ -70,15 +71,22 @@ SendCoinsEntry::~SendCoinsEntry()
 
 void SendCoinsEntry::on_MemoTextChanged(const QString &text)
 {
-    int maxLength = 256;
+    const spark::Params* params = spark::Params::get_default();
+    int maxLength = params->get_memo_bytes();
     bool isOverLimit = text.length() > maxLength;
 
     if (isOverLimit) {
-        ui->messageWarning->setText("Message exceeds character 256 character limit");
+        ui->messageWarning->setText(QString("Message exceeds %1 bytes limit").arg(maxLength));
         ui->messageWarning->setVisible(true);
         ui->messageTextLabel->setStyleSheet("border: 1px solid red;");
         ui->iconMessageWarning->setVisible(true);
     } else {
+        QString sanitized = text;
+        sanitized.remove(QRegExp("[\\x00-\\x1F\\x7F]"));
+        if (sanitized != text) {
+            ui->messageTextLabel->setText(sanitized);
+            return;
+        }
         ui->messageWarning->clear();
         ui->messageWarning->setVisible(false);
         ui->messageTextLabel->setStyleSheet("");
diff --git a/src/spark/primitives.h b/src/spark/primitives.h
index 09de4550eb..2bfa0c72bb 100644
--- a/src/spark/primitives.h
+++ b/src/spark/primitives.h
@@ -107,7 +107,15 @@ class CSparkOutputTx
     inline void SerializationOp(Stream& s, Operation ser_action) {
         READWRITE(address);
         READWRITE(amount);
-        READWRITE(memo);
+        if (ser_action.ForRead()) {
+            if (!s.empty()) {
+                READWRITE(memo);
+            } else {
+                memo = "";
+            }
+        } else {
+            READWRITE(memo);
+        }
     }
 };
 
diff --git a/src/spark/sparkwallet.cpp b/src/spark/sparkwallet.cpp
index d99a3f4810..9e5e0a49e8 100644
--- a/src/spark/sparkwallet.cpp
+++ b/src/spark/sparkwallet.cpp
@@ -743,6 +743,10 @@ std::vector<CRecipient> CSparkWallet::CreateSparkMintRecipients(
         unsigned char network = spark::GetNetworkType();
         std::string addr = outputs[i].address.encode(network);
         std::string memo = outputs[i].memo;
+        const std::size_t max_memo_size = outputs[i].address.get_params()->get_memo_bytes();
+        if (memo.length() > max_memo_size) {
+            throw std::runtime_error(strprintf("Memo exceeds maximum length of %d bytes", max_memo_size));
+        }
         CRecipient recipient = {script, CAmount(outputs[i].v), false, addr, memo};
         results.emplace_back(recipient);
     }