diff --git a/libavcodec/ws-snd1.c b/libavcodec/ws-snd1.c
index a419e3dfb5..057d4bfc29 100644
--- a/libavcodec/ws-snd1.c
+++ b/libavcodec/ws-snd1.c
@@ -45,7 +45,7 @@ static int ws_snd_decode_init(AVCodecContext * avctx)
 
 static int ws_snd_decode_frame(AVCodecContext *avctx,
                 void *data, int *data_size,
-                uint8_t *buf, int buf_size)
+                const uint8_t *buf, int buf_size)
 {
 //    WSSNDContext *c = avctx->priv_data;