diff --git a/DOCS/mplayer.1 b/DOCS/mplayer.1
index 16fb290654..58fabc28f1 100644
--- a/DOCS/mplayer.1
+++ b/DOCS/mplayer.1
@@ -1031,6 +1031,11 @@ The following options apply only to B frames :
                    higher quantizer for b frames)
                    default = 2.0
 
+  vb_qfactor=XXX   quantizer factor between b
+                   and i/p frames (larger means
+                   higher quantizer for b frames)
+                   default = 2.0
+
 In fixed quantizer mode you can use those options :
   vqscale, vmax_b_frames, vhq, vme, keyint