4 files changed, 29 insertions, 2 deletions
diff --git a/src/qt/forms/sendcoinsdialog.ui b/src/qt/forms/sendcoinsdialog.ui
index f13b0d9cf9..cc183908d4 100644
--- a/src/qt/forms/sendcoinsdialog.ui
+++ b/src/qt/forms/sendcoinsdialog.ui
@@ -1180,6 +1180,16 @@
              </item>
             </layout>
            </item>
+           <item>
+            <widget class="QCheckBox" name="optInRBF">
+             <property name="text">
+              <string>Request Replace-By-Fee</string>
+             </property>
+             <property name="toolTip">
+              <string>Indicates that the sender may wish to replace this transaction with a new one paying higher fees (prior to being confirmed).</string>
+             </property>
+            </widget>
+           </item>
           </layout>
          </widget>
         </item>
@@ -1190,8 +1200,8 @@
           </property>
           <property name="sizeHint" stdset="0">
            <size>
-            <width>800</width>
-            <height>1</height>
+            <width>40</width>
+            <height>5</height>
            </size>
           </property>
          </spacer>
diff --git a/src/qt/sendcoinsdialog.cpp b/src/qt/sendcoinsdialog.cpp
index 65ca007552..ed7eab03f3 100644
--- a/src/qt/sendcoinsdialog.cpp
+++ b/src/qt/sendcoinsdialog.cpp
@@ -114,6 +114,7 @@ SendCoinsDialog::SendCoinsDialog(const PlatformStyle *_platformStyle, QWidget *p
     ui->groupCustomFee->button((int)std::max(0, std::min(1, settings.value("nCustomFeeRadio").toInt())))->setChecked(true);
     ui->customFee->setValue(settings.value("nTransactionFee").toLongLong());
     ui->checkBoxMinimumFee->setChecked(settings.value("fPayOnlyMinFee").toBool());
+    ui->optInRBF->setCheckState(model->getDefaultWalletRbf() ? Qt::Checked : Qt::Unchecked);
     minimizeFeeSection(settings.value("fFeeSectionMinimized").toBool());
 }
 
@@ -247,6 +248,8 @@ void SendCoinsDialog::on_sendButton_clicked()
     else
         ctrl.nConfirmTarget = 0;
 
+    ctrl.signalRbf = ui->optInRBF->isChecked();
+
     prepareStatus = model->prepareTransaction(currentTransaction, &ctrl);
 
     // process prepareStatus and on error generate message shown to user
@@ -326,6 +329,13 @@ void SendCoinsDialog::on_sendButton_clicked()
     questionString.append(QString("<span style='font-size:10pt;font-weight:normal;'><br />(=%2)</span>")
         .arg(alternativeUnits.join(" " + tr("or") + "<br />")));
 
+    if (ui->optInRBF->isChecked())
+    {
+        questionString.append("<hr /><span>");
+        questionString.append(tr("This transaction signals replaceability (optin-RBF)."));
+        questionString.append("</span>");
+    }
+
     SendConfirmationDialog confirmationDialog(tr("Confirm send coins"),
         questionString.arg(formatted.join("<br />")), SEND_CONFIRM_DELAY, this);
     confirmationDialog.exec();
diff --git a/src/qt/walletmodel.cpp b/src/qt/walletmodel.cpp
index 878b7d58ae..ebcac53c25 100644
--- a/src/qt/walletmodel.cpp
+++ b/src/qt/walletmodel.cpp
@@ -706,3 +706,8 @@ int WalletModel::getDefaultConfirmTarget() const
 {
     return nTxConfirmTarget;
 }
+
+bool WalletModel::getDefaultWalletRbf() const
+{
+    return fWalletRbf;
+}
diff --git a/src/qt/walletmodel.h b/src/qt/walletmodel.h
index cd7585635f..78e45dc369 100644
--- a/src/qt/walletmodel.h
+++ b/src/qt/walletmodel.h
@@ -213,6 +213,8 @@ public:
 
     int getDefaultConfirmTarget() const;
 
+    bool getDefaultWalletRbf() const;
+
 private:
     CWallet *wallet;
     bool fHaveWatchOnly;