diff --git a/NEWS b/NEWS
index 47d6b7b98..47e7f1be4 100644
--- a/NEWS
+++ b/NEWS
@@ -1,4 +1,6 @@
 ver 0.22.7 (not yet released)
+* decoder
+  - ffmpeg: fix build problem with FFmpeg 3.4
 
 ver 0.22.6 (2021/02/16)
 * fix missing tags on songs in queue
diff --git a/src/decoder/plugins/FfmpegDecoderPlugin.cxx b/src/decoder/plugins/FfmpegDecoderPlugin.cxx
index b274ae4fb..889062ee6 100644
--- a/src/decoder/plugins/FfmpegDecoderPlugin.cxx
+++ b/src/decoder/plugins/FfmpegDecoderPlugin.cxx
@@ -467,7 +467,11 @@ FfmpegCheckTag(DecoderClient &client, InputStream *is,
 static bool
 IsSeekable(const AVFormatContext &format_context) noexcept
 {
+#if LIBAVFORMAT_VERSION_INT >= AV_VERSION_INT(58, 6, 100)
 	return (format_context.ctx_flags & AVFMTCTX_UNSEEKABLE) != 0;
+#else
+	return false;
+#endif
 }
 
 static void