diff --git a/forms/mainwindow.ui b/forms/mainwindow.ui
index 0a71bce5..1a2268a2 100644
--- a/forms/mainwindow.ui
+++ b/forms/mainwindow.ui
@@ -2142,6 +2142,11 @@
                  <attribute name="verticalHeaderVisible">
                   <bool>false</bool>
                  </attribute>
+                 <column>
+                  <property name="text">
+                   <string>Type</string>
+                  </property>
+                 </column>
                  <column>
                   <property name="text">
                    <string>Key</string>
diff --git a/include/mainwindow.h b/include/mainwindow.h
index 4eae446f..455e79eb 100644
--- a/include/mainwindow.h
+++ b/include/mainwindow.h
@@ -388,7 +388,7 @@ private:
     void redrawMetatileSelection();
 
     QObjectList shortcutableObjects() const;
-    QTableWidgetItem * createNewCustomHeaderItem(QJsonValue value);
+    void addCustomHeaderValue(QString key, QJsonValue value, bool isNew = false);
 };
 
 enum MapListUserRoles {
diff --git a/src/editor.cpp b/src/editor.cpp
index 50da1ca2..bf748b7c 100644
--- a/src/editor.cpp
+++ b/src/editor.cpp
@@ -1951,30 +1951,34 @@ void Editor::updateCustomMapHeaderValues(QTableWidget *table)
     QMap<QString, QJsonValue> fields;
     for (int row = 0; row < table->rowCount(); row++) {
         QString key = "";
-        QString value = "";
-        QTableWidgetItem *keyItem = table->item(row, 0);
-        QTableWidgetItem *valueItem = table->item(row, 1);
+        QTableWidgetItem *typeItem = table->item(row, 0);
+        QTableWidgetItem *keyItem = table->item(row, 1);
+        QTableWidgetItem *valueItem = table->item(row, 2);
+
         if (keyItem) key = keyItem->text();
-        if (!key.isEmpty() && valueItem) {
-            // Use the original table value to determine which type the input text should be saved as.
-            QJsonValue value = valueItem->data(Qt::UserRole).toJsonValue();
-            switch (value.type())
-            {
-            case QJsonValue::String:
-                value = QJsonValue(valueItem->text());
-                break;
-            case QJsonValue::Double:
-                value = QJsonValue(valueItem->text().toInt());
-                break;
-            case QJsonValue::Bool:
-                value = QJsonValue(valueItem->checkState() == Qt::Checked);
-                break;
-            default:
-                // Arrays and objects can't be updated via the table, just preserve the original value.
-                break;
-            }
-            fields[key] = value;
+        if (key.isEmpty() || !typeItem || !valueItem)
+            continue;
+
+        // Read which JSON type to save the value as from the table data
+        QJsonValue::Type type = static_cast<QJsonValue::Type>(typeItem->data(Qt::UserRole).toInt());
+        QJsonValue value;
+        switch (type)
+        {
+        case QJsonValue::String:
+            value = QJsonValue(valueItem->text());
+            break;
+        case QJsonValue::Double:
+            value = QJsonValue(valueItem->text().toInt());
+            break;
+        case QJsonValue::Bool:
+            value = QJsonValue(valueItem->checkState() == Qt::Checked);
+            break;
+        default:
+            // All other types will just be preserved
+            value = valueItem->data(Qt::UserRole).toJsonValue();
+            break;
         }
+        fields[key] = value;
     }
     map->customHeaders = fields;
     emit editedMapData();
diff --git a/src/mainwindow.cpp b/src/mainwindow.cpp
index 94055e76..e8787184 100644
--- a/src/mainwindow.cpp
+++ b/src/mainwindow.cpp
@@ -802,12 +802,8 @@ void MainWindow::displayMapProperties() {
     // Custom fields table.
     ui->tableWidget_CustomHeaderFields->blockSignals(true);
     ui->tableWidget_CustomHeaderFields->setRowCount(0);
-    for (auto it = map->customHeaders.begin(); it != map->customHeaders.end(); it++) {
-        int rowIndex = ui->tableWidget_CustomHeaderFields->rowCount();
-        ui->tableWidget_CustomHeaderFields->insertRow(rowIndex);
-        ui->tableWidget_CustomHeaderFields->setItem(rowIndex, 0, new QTableWidgetItem(it.key()));
-        ui->tableWidget_CustomHeaderFields->setItem(rowIndex, 1, createNewCustomHeaderItem(it.value()));
-    }
+    for (auto it = map->customHeaders.begin(); it != map->customHeaders.end(); it++)
+        addCustomHeaderValue(it.key(), it.value());
     ui->tableWidget_CustomHeaderFields->horizontalHeader()->setSectionResizeMode(QHeaderView::ResizeToContents);
     ui->tableWidget_CustomHeaderFields->blockSignals(false);
 }
@@ -3080,36 +3076,65 @@ void MainWindow::togglePreferenceSpecificUi() {
         ui->actionOpen_Project_in_Text_Editor->setEnabled(true);
 }
 
-QTableWidgetItem * MainWindow::createNewCustomHeaderItem(QJsonValue value) {
-    QTableWidgetItem * tableItem;
-    switch (value.type())
+void MainWindow::addCustomHeaderValue(QString key, QJsonValue value, bool isNew) {
+    QTableWidgetItem * valueItem;
+    QJsonValue::Type type = value.type();
+    switch (type)
     {
     case QJsonValue::String:
     case QJsonValue::Double:
-        tableItem = new QTableWidgetItem(ParseUtil::jsonToQString(value));
+        valueItem = new QTableWidgetItem(ParseUtil::jsonToQString(value));
         break;
     case QJsonValue::Bool:
-        tableItem = new QTableWidgetItem("");
-        tableItem->setCheckState(value.toBool() ? Qt::Checked : Qt::Unchecked);
+        valueItem = new QTableWidgetItem("");
+        valueItem->setCheckState(value.toBool() ? Qt::Checked : Qt::Unchecked);
         break;
     default:
-        tableItem = new QTableWidgetItem("This value cannot be edited from this table");
-        tableItem->setFlags(Qt::NoItemFlags);
+        valueItem = new QTableWidgetItem("This value cannot be edited from this table");
+        valueItem->setFlags(Qt::NoItemFlags);
+        valueItem->setData(Qt::UserRole, value); // Preserve the value for writing to the file
         break;
     }
-    tableItem->setData(Qt::UserRole, value); // Save the original value/type for when it's written back to the project
-    return tableItem;
+
+    const QHash<QJsonValue::Type, QString> typeToName = {
+        {QJsonValue::Bool, "Bool"},
+        {QJsonValue::Double, "Number"},
+        {QJsonValue::String, "String"},
+        {QJsonValue::Array, "Array"},
+        {QJsonValue::Object, "Object"},
+        {QJsonValue::Null, "Null"},
+        {QJsonValue::Undefined, "Null"},
+    };
+    QTableWidgetItem * typeItem = new QTableWidgetItem(typeToName[type]);
+    typeItem->setFlags(Qt::ItemIsEnabled);
+    typeItem->setData(Qt::UserRole, type); // Record the type for writing to the file
+
+    int rowIndex = this->ui->tableWidget_CustomHeaderFields->rowCount();
+    this->ui->tableWidget_CustomHeaderFields->insertRow(rowIndex);
+    this->ui->tableWidget_CustomHeaderFields->setItem(rowIndex, 0, typeItem);
+    this->ui->tableWidget_CustomHeaderFields->setItem(rowIndex, 1, new QTableWidgetItem(key));
+    this->ui->tableWidget_CustomHeaderFields->setItem(rowIndex, 2, valueItem);
+
+    if (isNew) {
+        valueItem->setText(""); // Erase the "0" in new numbers
+        this->ui->tableWidget_CustomHeaderFields->selectRow(rowIndex);
+        this->editor->updateCustomMapHeaderValues(this->ui->tableWidget_CustomHeaderFields);
+    }
 }
 
 void MainWindow::on_pushButton_AddCustomHeaderField_clicked()
 {
-    int rowIndex = this->ui->tableWidget_CustomHeaderFields->rowCount();
-    this->ui->tableWidget_CustomHeaderFields->insertRow(rowIndex);
-    this->ui->tableWidget_CustomHeaderFields->selectRow(rowIndex);
-    // TODO: New items default to string, allow type selection
-    QJsonValue defaultValue = QJsonValue(QString(""));
-    this->ui->tableWidget_CustomHeaderFields->setItem(rowIndex, 1, createNewCustomHeaderItem(defaultValue));
-    this->editor->updateCustomMapHeaderValues(this->ui->tableWidget_CustomHeaderFields);
+    const QMap<QString, QJsonValue> valueTypes = {
+        {"String",  QJsonValue(QString(""))},
+        {"Number",  QJsonValue(0)},
+        {"Boolean", QJsonValue(false)},
+    };
+
+    bool ok;
+    QStringList typeNames = valueTypes.keys();
+    QString selection = QInputDialog::getItem(this, "", "Choose Value Type", typeNames, typeNames.indexOf("String"), false, &ok);
+    if (ok)
+        addCustomHeaderValue("", valueTypes[selection], true);
 }
 
 void MainWindow::on_pushButton_DeleteCustomHeaderField_clicked()