diff --git a/grid-view.c b/grid-view.c
index a34c5a08..078a0da4 100644
--- a/grid-view.c
+++ b/grid-view.c
@@ -184,9 +184,10 @@ grid_view_insert_cells(struct grid *gd, u_int px, u_int py, u_int nx)
 	px = grid_view_x(gd, px);
 	py = grid_view_y(gd, py);
 
-	sx = grid_view_x(gd, gd->linedata[py].cellsize);
-	if (sx < px + nx)
-		sx = px + nx;
+	if (gd->linedata[py].cellsize + nx < gd->sx)
+		sx = grid_view_x(gd, gd->linedata[py].cellsize + nx);
+	else
+		sx = grid_view_x(gd, gd->sx);
 
 	if (px == sx - 1)
 		grid_clear(gd, px, py, 1, 1);