diff --git a/source/sw/src/draw.cpp b/source/sw/src/draw.cpp
index 6523ede27..4991de3e5 100644
--- a/source/sw/src/draw.cpp
+++ b/source/sw/src/draw.cpp
@@ -2223,7 +2223,7 @@ drawscreen(PLAYERp pp)
         if (dimensionmode == 6)
         {
             // only clear the actual window.
-            twod->AddColorOnlyQuad(windowxy1.x, windowxy1.y, windowxy2.x - windowxy1.x + 1, windowxy2.y - windowxy1.y - 1, 0xff000000);
+            twod->AddColorOnlyQuad(windowxy1.x, windowxy1.y, windowxy2.x - windowxy1.x, windowxy2.y - windowxy1.y, 0xff000000);
             renderDrawMapView(tx, ty, zoom, tang);
         }