diff --git a/libavcodec/wmalosslessdec.c b/libavcodec/wmalosslessdec.c
index ee4eb03bc6..72535d5030 100644
--- a/libavcodec/wmalosslessdec.c
+++ b/libavcodec/wmalosslessdec.c
@@ -1028,6 +1028,7 @@ static int decode_frame(WmallDecodeCtx *s)
     if ((ret = ff_get_buffer(s->avctx, s->frame, 0)) < 0) {
         /* return an error if no frame could be decoded at all */
         s->packet_loss = 1;
+        s->frame->nb_samples = 0;
         return ret;
     }
     for (i = 0; i < s->num_channels; i++) {