diff --git a/src/merge/mkvmerge.cpp b/src/merge/mkvmerge.cpp
index 721c1d5b5..027668de5 100644
--- a/src/merge/mkvmerge.cpp
+++ b/src/merge/mkvmerge.cpp
@@ -216,7 +216,8 @@ set_usage() {
     "  --language <TID:lang>    Sets the language for the track (ISO639-2\n"
     "                           code, see --list-languages).\n"
     "  -t, --tags <TID:file>    Read tags for the track from a XML file.\n"
-    "  --aac-is-sbr <TID>       Track with the ID is HE-AAC/AAC+/SBR-AAC.\n"
+    "  --aac-is-sbr <TID[:0|1]> The track with the ID is HE-AAC/AAC+/SBR-AAC\n"
+    "                           or not. The value ':1' can be omitted.\n"
     "  --timecodes <TID:file>   Read the timecodes to be used from a file.\n"
     "  --default-duration <TID:Xs|ms|us|ns|fps>\n"
     "                           Force the default duration of a track to X.\n"