diff --git a/uppsrc/Draw/DrawData.cpp b/uppsrc/Draw/DrawData.cpp
index f78d6f1d5..20d20111f 100644
--- a/uppsrc/Draw/DrawData.cpp
+++ b/uppsrc/Draw/DrawData.cpp
@@ -103,7 +103,7 @@ void Draw::DrawDataOp(int x, int y, int cx, int cy, const String& data, const ch
 		if((cx > 2048 || cy > 2048) && (GetInfo() & DATABANDS)) {
 			int yy = 0;
 			while(yy < cy) {
-				int ccy = min(cy - yy, 32);
+				int ccy = min(cy - yy, 32); // Must be multiply of 4 because of dithering
 				ImageBuffer ib(cx, ccy);
 				dd->Render(ib);
 				DrawImageBandRLE(*this, x, y + yy, ib, 16);