diff --git a/MapPresent/MapPresent.cpp b/MapPresent/MapPresent.cpp
index 8359e7a..4c113f2 100644
--- a/MapPresent/MapPresent.cpp
+++ b/MapPresent/MapPresent.cpp
@@ -123,7 +123,8 @@ void MapPresent::paintEvent(QPaintEvent* ev)
 	if (_updated_index_list.size()) {
 		QPainter pic_painter(&_paint_buffer);
 
-		for (auto unit_idx : _updated_index_list) {
+		const int update_batch_count = 1200;
+		for (auto unit_idx : _updated_index_list.mid(0, update_batch_count)) {
 			pic_painter.save();
 
 			auto opt = _visible_units[unit_idx];
@@ -147,7 +148,10 @@ void MapPresent::paintEvent(QPaintEvent* ev)
 			pic_painter.restore();
 		}
 
-		_updated_index_list.clear();
+		_updated_index_list = _updated_index_list.mid(update_batch_count);
+		if (_updated_index_list.size()) {
+			this->update();
+		}
 	}
 
 	QPainter widget_painter(this);