diff --git a/src/common/Vec2.h b/src/common/Vec2.h
index 34133f785..c09055a78 100644
--- a/src/common/Vec2.h
+++ b/src/common/Vec2.h
@@ -380,6 +380,18 @@ public:
 		return point.X >= pos.X && point.X < pos.X + size.X && point.Y >= pos.Y && point.Y < pos.Y + size.Y;
 	}
 
+	template<typename S = T, typename = std::enable_if_t<std::is_integral_v<S>>>
+	inline Vec2<T> TopLeft() const
+	{
+		return pos;
+	}
+
+	template<typename S = T, typename = std::enable_if_t<std::is_integral_v<S>>>
+	inline Vec2<T> BottomRight() const
+	{
+		return pos + size - Vec2<T>(1, 1);
+	}
+
 	template<typename S>
 	Rect<decltype(std::declval<T>() + std::declval<S>())> Inset(S delta) const
 	{
diff --git a/src/simulation/Simulation.cpp b/src/simulation/Simulation.cpp
index bab82c77a..9767137e4 100644
--- a/src/simulation/Simulation.cpp
+++ b/src/simulation/Simulation.cpp
@@ -312,7 +312,7 @@ void Simulation::Load(const GameSave *save, bool includePressure, Vec2<int> bloc
 
 std::unique_ptr<GameSave> Simulation::Save(bool includePressure, Rect<int> partR) // particle coordinates
 {
-	auto blockR = RectBetween(partR.pos / CELL, (partR.pos + partR.size) / CELL);
+	auto blockR = RectBetween(partR.TopLeft() / CELL, partR.BottomRight() / CELL);
 	auto blockP = blockR.pos;
 
 	auto newSave = std::make_unique<GameSave>(blockR.size);