diff --git a/a52/pcm_a52.c b/a52/pcm_a52.c
index 289a9db..9da8897 100644
--- a/a52/pcm_a52.c
+++ b/a52/pcm_a52.c
@@ -563,7 +563,7 @@ static void a52_dump(snd_pcm_ioplug_t *io, snd_output_t *out)
 	snd_output_printf(out, "Its setup is:\n");
 	snd_pcm_dump_setup(pcm, out);
 	snd_output_printf(out, "  %-13s: %s\n", "av_format", av_get_sample_fmt_name(rec->av_format));
-	snd_output_printf(out, "  %-13s: %i\n", "av_frame_size", rec->avctx->frame_size);
+	snd_output_printf(out, "  %-13s: %i\n", "av_frame_size", rec->avctx ? rec->avctx->frame_size : -1);
 	snd_output_printf(out, "  %-13s: %i\n", "remain", rec->remain);
 	snd_output_printf(out, "  %-13s: %i\n", "filled", rec->filled);
 	snd_output_printf(out, "Slave: ");