diff --git a/ubb-la/gui.c b/ubb-la/gui.c
index 1f90294..117a30b 100644
--- a/ubb-la/gui.c
+++ b/ubb-la/gui.c
@@ -300,7 +300,7 @@ static void show_buffer(const uint8_t *buf, int skip, int nibbles,
 	int d, dp;
 
 	xm = (x0+x1) >> 1;
-	dp = pos-((nibbles+skip) >> 1);
+	dp = pos-((nibbles-skip) >> 1);
 	DEBUG("show: %d-%d Sa; %d-%d pix; pos %d dp %d; xm %d xcenter %d\n",
 	    skip, nibbles, x0, x1, pos, dp, xm, XCENTER);
 	if (zoom < 0) {