diff --git a/libavcodec/libvorbis.c b/libavcodec/libvorbis.c
index 7e75d1d7cb1233ffeb51c25b9096ac27285354f2..ef56c25ac9888eb87043eda6231f727b4a10c419 100644
--- a/libavcodec/libvorbis.c
+++ b/libavcodec/libvorbis.c
@@ -55,7 +55,7 @@ typedef struct OggVorbisContext {
 } OggVorbisContext ;
 
 static const AVOption options[]={
-{"iblock", "Sets the impulse block bias", offsetof(OggVorbisContext, iblock), FF_OPT_TYPE_DOUBLE, 0, -15, 0, AV_OPT_FLAG_ENCODING_PARAM},
+{"iblock", "Sets the impulse block bias", offsetof(OggVorbisContext, iblock), FF_OPT_TYPE_DOUBLE, 0, -15, 0, AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_ENCODING_PARAM},
 {NULL}
 };
 static const AVClass class = { "libvorbis", av_default_item_name, options, LIBAVUTIL_VERSION_INT };