diff --git a/ui/sdl2-gl.c b/ui/sdl2-gl.c
index 83b71853d1557a1416cb102b9342d43bc87fe580..1bf4542d8d9659340ad9e677dbdd32b589dc1075 100644
--- a/ui/sdl2-gl.c
+++ b/ui/sdl2-gl.c
@@ -124,6 +124,11 @@ void sdl2_gl_redraw(struct sdl2_console *scon)
 {
     assert(scon->opengl);
 
+    if (scon->scanout_mode) {
+        /* sdl2_gl_scanout_flush actually only care about
+         * the first argument. */
+        return sdl2_gl_scanout_flush(&scon->dcl, 0, 0, 0, 0);
+    }
     if (scon->surface) {
         sdl2_gl_render_surface(scon);
     }