diff --git a/glamor/glamor_copy.c b/glamor/glamor_copy.c
index 8a329d2..cd970ec 100644
--- a/glamor/glamor_copy.c
+++ b/glamor/glamor_copy.c
@@ -235,11 +235,11 @@ glamor_copy_cpu_fbo(DrawablePtr src,
 
         if (src->bitsPerPixel > 1)
             fbCopyNto1(src, &src_pix->drawable, gc, box, nbox,
-                       dst_xoff + dx, dst_yoff + dy, reverse, upsidedown,
+                       dx - dst_xoff, dy - dst_yoff, reverse, upsidedown,
                        bitplane, closure);
         else
             fbCopy1toN(src, &src_pix->drawable, gc, box, nbox,
-                       dst_xoff + dx, dst_yoff + dy, reverse, upsidedown,
+                       dx - dst_xoff, dy - dst_yoff, reverse, upsidedown,
                        bitplane, closure);
 
         glamor_upload_boxes(dst_pixmap, box, nbox, 0, 0, 0, 0,