diff --git a/lib/codeclib.c b/lib/codeclib.c
index 35886a9a9..e02f1e32c 100644
--- a/lib/codeclib.c
+++ b/lib/codeclib.c
@@ -397,6 +397,7 @@ static struct codec_def_s __codec_defs[] = {
 		.default_channels = 1,
 		.default_ptime = 20,
 		.packetizer = packetizer_samplestream,
+		.format_cmp = format_cmp_ignore,
 		.bits_per_sample = 8,
 		.media_type = MT_AUDIO,
 		.codec_type = &codec_type_avcodec,
@@ -415,6 +416,7 @@ static struct codec_def_s __codec_defs[] = {
 		.default_ptime = 20,
 		.packetizer = packetizer_samplestream,
 		.bits_per_sample = 8,
+		.format_cmp = format_cmp_ignore,
 		.media_type = MT_AUDIO,
 		.codec_type = &codec_type_avcodec,
 		.silence_pattern = STR_CONST_INIT("\xff"),