diff --git a/ext/mpg123/gstmpg123audiodec.c b/ext/mpg123/gstmpg123audiodec.c
index bdbb3e9fcd..2be008245e 100644
--- a/ext/mpg123/gstmpg123audiodec.c
+++ b/ext/mpg123/gstmpg123audiodec.c
@@ -196,6 +196,7 @@ void
 gst_mpg123_audio_dec_init (GstMpg123AudioDec * mpg123_decoder)
 {
   mpg123_decoder->handle = NULL;
+  gst_audio_decoder_set_needs_format (GST_AUDIO_DECODER (mpg123_decoder), TRUE);
 }