--- a/src/decoder/plugins/FfmpegIo.hxx
+++ b/src/decoder/plugins/FfmpegIo.hxx
@@ -21,6 +21,7 @@
 #define MPD_FFMPEG_IO_HXX
 
 extern "C" {
+#include "libavutil/error.h"
 #include "libavformat/avio.h"
 }