diff --git a/README.md b/README.md
index f0888f5..61a6fb0 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,8 @@ Command line usage
     $ python -m pysstv -h
     usage: __main__.py [-h]
                   [--mode {MartinM2,MartinM1,Robot24BW,ScottieS2,ScottieS1,Robot8BW,PasokonP3,PasokonP5,PasokonP7}]
-                  [--rate RATE] [--bits BITS]
+                  [--rate RATE] [--bits BITS] [--vox] [--fskid FSKID]
+                  [--chan CHAN]
                   image.png output.wav
 
     Converts an image to an SSTV modulated WAV file.
@@ -32,6 +33,9 @@ Command line usage
                             image mode (default: Martin M1)
       --rate RATE           sampling rate (default: 48000)
       --bits BITS           bits per sample (default: 16)
+      --vox                 add VOX tones at the beginning
+      --fskid FSKID         add FSKID at the end
+      --chan CHAN           number of channels (default: mono)
 
 Python interface
 ----------------