diff --git a/src/decoder/plugins/SndfileDecoderPlugin.cxx b/src/decoder/plugins/SndfileDecoderPlugin.cxx
index 58714e4c3..465194f13 100644
--- a/src/decoder/plugins/SndfileDecoderPlugin.cxx
+++ b/src/decoder/plugins/SndfileDecoderPlugin.cxx
@@ -130,7 +130,7 @@ sndfile_vio_tell(void *user_data)
  * This SF_VIRTUAL_IO implementation wraps MPD's #InputStream to a
  * libsndfile stream.
  */
-static SF_VIRTUAL_IO vio = {
+static constexpr SF_VIRTUAL_IO vio = {
 	sndfile_vio_get_filelen,
 	sndfile_vio_seek,
 	sndfile_vio_read,
@@ -202,7 +202,8 @@ sndfile_stream_decode(DecoderClient &client, InputStream &is)
 	info.format = 0;
 
 	SndfileInputStream sis{&client, is};
-	SNDFILE *const sf = sf_open_virtual(&vio, SFM_READ, &info, &sis);
+	SNDFILE *const sf = sf_open_virtual(const_cast<SF_VIRTUAL_IO *>(&vio),
+					    SFM_READ, &info, &sis);
 	if (sf == nullptr) {
 		FormatWarning(sndfile_domain, "sf_open_virtual() failed: %s",
 			      sf_strerror(nullptr));
@@ -274,7 +275,8 @@ sndfile_scan_stream(InputStream &is, TagHandler &handler) noexcept
 	info.format = 0;
 
 	SndfileInputStream sis{nullptr, is};
-	SNDFILE *const sf = sf_open_virtual(&vio, SFM_READ, &info, &sis);
+	SNDFILE *const sf = sf_open_virtual(const_cast<SF_VIRTUAL_IO *>(&vio),
+					    SFM_READ, &info, &sis);
 	if (sf == nullptr)
 		return false;