diff --git a/libavformat/flvenc.c b/libavformat/flvenc.c
index d998f5962c..5d448a1b49 100644
--- a/libavformat/flvenc.c
+++ b/libavformat/flvenc.c
@@ -65,6 +65,9 @@ static int get_audio_flags(AVCodecContext *enc){
     case CODEC_ID_PCM_S16LE:
 	flags |= 0x2;
 	break;
+    case CODEC_ID_ADPCM_SWF:
+	flags |= 0x10;
+	break;
     case 0:
         flags |= enc->codec_tag<<4;
         break;