diff --git a/src/nostalgia/core/studio/tilesheeteditormodel.cpp b/src/nostalgia/core/studio/tilesheeteditormodel.cpp
index 2951d793..e769d4a2 100644
--- a/src/nostalgia/core/studio/tilesheeteditormodel.cpp
+++ b/src/nostalgia/core/studio/tilesheeteditormodel.cpp
@@ -380,10 +380,10 @@ void TileSheetEditorModel::paste() {
 
 void TileSheetEditorModel::drawCommand(const geo::Point &pt, std::size_t palIdx) noexcept {
 	const auto &activeSubSheet = m_img.getSubSheet(m_activeSubsSheetIdx);
-	const auto idx = activeSubSheet.idx(pt);
-	if (idx >= activeSubSheet.pixelCnt(m_img.bpp)) {
+	if (pt.x >= activeSubSheet.columns * TileWidth || pt.y >= activeSubSheet.rows * TileHeight) {
 		return;
 	}
+	const auto idx = activeSubSheet.idx(pt);
 	if (m_ongoingDrawCommand) {
 		m_updated = m_updated || m_ongoingDrawCommand->append(idx);
 	} else if (activeSubSheet.getPixel(m_img.bpp, idx) != palIdx) {
@@ -414,11 +414,11 @@ void TileSheetEditorModel::setActiveSubsheet(const TileSheet::SubSheetIdx &idx)
 }
 
 void TileSheetEditorModel::fill(const geo::Point &pt, int palIdx) noexcept {
-	const auto s = m_img.getSubSheet(m_activeSubsSheetIdx);
+	const auto &s = m_img.getSubSheet(m_activeSubsSheetIdx);
 	// build idx list
 	ox::Array<bool, PixelsPerTile> updateMap = {};
 	const auto oldColor = s.getPixel(m_img.bpp, pt);
-	if (oldColor == palIdx) {
+	if (pt.x >= s.columns * TileWidth || pt.y >= s.rows * TileHeight) {
 		return;
 	}
 	getFillPixels(updateMap.data(), pt, oldColor);