diff --git a/GPU/Software/TransformUnit.cpp b/GPU/Software/TransformUnit.cpp
index aa0073e175..acdbe9f57e 100644
--- a/GPU/Software/TransformUnit.cpp
+++ b/GPU/Software/TransformUnit.cpp
@@ -97,8 +97,8 @@ DrawingCoords TransformUnit::ScreenToDrawing(const ScreenCoords& coords)
 {
 	DrawingCoords ret;
 	// TODO: What to do when offset > coord?
-	ret.x = (((u32)coords.x - gstate.getOffsetX16()) / 16) & 0x3ff;
-	ret.y = (((u32)coords.y - gstate.getOffsetY16()) / 16) & 0x3ff;
+	ret.x = ((s32)coords.x - gstate.getOffsetX16()) / 16;
+	ret.y = ((s32)coords.y - gstate.getOffsetY16()) / 16;
 	ret.z = coords.z;
 	return ret;
 }
diff --git a/GPU/Software/TransformUnit.h b/GPU/Software/TransformUnit.h
index 9cda18df7f..0a54a088c0 100644
--- a/GPU/Software/TransformUnit.h
+++ b/GPU/Software/TransformUnit.h
@@ -62,17 +62,17 @@ struct ScreenCoords
 struct DrawingCoords
 {
 	DrawingCoords() {}
-	DrawingCoords(u10 x, u10 y, u16 z) : x(x), y(y), z(z) {}
+	DrawingCoords(s16 x, s16 y, u16 z) : x(x), y(y), z(z) {}
 
-	u10 x;
-	u10 y;
+	s16 x;
+	s16 y;
 	u16 z;
 
-	Vec2<u10> xy() const { return Vec2<u10>(x, y); }
+	Vec2<s16> xy() const { return Vec2<s16>(x, y); }
 
 	DrawingCoords operator * (const float t) const
 	{
-		return DrawingCoords((u10)(x * t), (u10)(y * t), (u16)(z * t));
+		return DrawingCoords((s16)(x * t), (s16)(y * t), (u16)(z * t));
 	}
 
 	DrawingCoords operator + (const DrawingCoords& oth) const