diff --git a/libavcodec/wavpackenc.c b/libavcodec/wavpackenc.c
index 9271e87990..33a5dfcc89 100644
--- a/libavcodec/wavpackenc.c
+++ b/libavcodec/wavpackenc.c
@@ -2592,7 +2592,16 @@ static int wavpack_encode_block(WavPackEncodeContext *s,
         s->avctx->ch_layout.u.mask != AV_CH_LAYOUT_STEREO) {
         put_metadata_block(&pb, WP_ID_CHANINFO, 5);
         bytestream2_put_byte(&pb, s->avctx->ch_layout.nb_channels);
-        bytestream2_put_le32(&pb, s->avctx->ch_layout.u.mask);
+        if (s->avctx->ch_layout.u.mask >> 32)
+            bytestream2_put_le32(&pb, 0);
+        else
+            bytestream2_put_le32(&pb, s->avctx->ch_layout.u.mask);
+        bytestream2_put_byte(&pb, 0);
+    } else if (s->flags & WV_INITIAL_BLOCK &&
+               s->avctx->ch_layout.order == AV_CHANNEL_ORDER_UNSPEC) {
+        put_metadata_block(&pb, WP_ID_CHANINFO, 5);
+        bytestream2_put_byte(&pb, s->avctx->ch_layout.nb_channels);
+        bytestream2_put_le32(&pb, 0);
         bytestream2_put_byte(&pb, 0);
     }