diff --git a/src/win32screen.c b/src/win32screen.c
index a14da75e..1ef5a67f 100644
--- a/src/win32screen.c
+++ b/src/win32screen.c
@@ -404,10 +404,10 @@ void Screen_FillRect(int x, int y, int w, int h, byte color)
 void Update_rect(short x, short y, unsigned short width, unsigned short height)
 {
   RECT rect;
-  rect.left = x;
-  rect.top = y;
-  rect.right = x + width;
-  rect.bottom = y + height;
+  rect.left = x * Pixel_width;
+  rect.top = y * Pixel_height;
+  rect.right = (x + width) * Pixel_width;
+  rect.bottom = (y + height) * Pixel_height;
   InvalidateRect(Win32_hwnd, &rect, TRUE);
 }