diff --git a/libavformat/rawenc.c b/libavformat/rawenc.c
index f8c267c4c9..26c7e8fef1 100644
--- a/libavformat/rawenc.c
+++ b/libavformat/rawenc.c
@@ -79,7 +79,7 @@ static int adx_write_trailer(AVFormatContext *s)
 
     if (pb->seekable & AVIO_SEEKABLE_NORMAL) {
         int64_t file_size = avio_tell(pb);
-        uint64_t sample_count = (file_size - 36) / par->channels / 18 * 32;
+        uint64_t sample_count = (file_size - 36) / par->ch_layout.nb_channels / 18 * 32;
         if (sample_count <= UINT32_MAX) {
             avio_seek(pb, 12, SEEK_SET);
             avio_wb32(pb, sample_count);