diff --git a/include/core/converter.h b/include/core/converter.h
index 198dea4d..3833e0d6 100644
--- a/include/core/converter.h
+++ b/include/core/converter.h
@@ -68,9 +68,17 @@ struct DefaultConverter {
     static T fromJson(const QJsonValue& json, QStringList* errors = nullptr) {
         const QVariant v = json.toVariant();
         if (!v.canConvert<T>()) {
-            if (errors) errors->append(QString("Can't convert from type '%1'").arg(v.typeName()));
-            // Failed conversion will return a default-constructed object below
+            if (errors) errors->append(QString("Can't convert from JSON to type '%1'").arg(v.typeName()));
+        } else {
+            // 'canConvert' is only true if a conversion between types is theoretically possible,
+            // not necessarily if this value can be converted. e.g. "2" can be converted to int (2),
+            // but "hello world" cannot be converted to int and becomes 0.
+            T value;
+            bool ok = QMetaType::convert(v.metaType(), v.constData(), QMetaType::fromType<T>(), &value);
+            if (ok) return value;
+            else if (errors) errors->append(QString("Failed to convert JSON value to type '%1'").arg(v.typeName()));
         }
+        // For failed conversion, return a default constructed value.
         return v.value<T>();
     }
 
diff --git a/include/core/fieldmanager.h b/include/core/fieldmanager.h
index ed2fcccd..2689a083 100644
--- a/include/core/fieldmanager.h
+++ b/include/core/fieldmanager.h
@@ -23,6 +23,13 @@
 //    QList<QString> options = {"hello","hi there"};
 //    FieldInterface* fi = makeFieldInterface(&someField, options);
 //    fi->set(QJsonValue("5")); // someField is now "hello" (defaults to first element), error messages returned
+//
+// If a type or value is given that cannot be converted to the destination type, the field remains unchanged.
+//    int someField = 0;
+//    int min = 1, max = 4;
+//    FieldInterface* fi = makeFieldInterface(&someField, min, max);
+//    fi->set(QJsonValue()); // Cannot convert type. someField is still 0, error messages returned
+//    fi->set(QJsonValue("hi there")); // Cannot convert value. someField is still 0, error messages returned
 
 // Base class lets us use the interface without any type information.
 class FieldInterface {