diff --git a/README.md b/README.md
index f89db8261851fa36fa67a3362fc7c85f208a680e..1ae564e4a7a400edf3d326a1eeb144c9dd58cf02 100644
--- a/README.md
+++ b/README.md
@@ -53,6 +53,7 @@ The `bamcalib` expect the following parameters:
 
 - `-c`, `--cal-prefix <cal_prefix>`    calibration prefix added to the chromosome name of the calibration genome (default: `calib_`)
 - `-h`, `--help`                       Print help information
+- `-s`, `--scaling <SCALING>`          multiply the OR by this value (must be the same across sample) [default: 1000]
 - `-n`, `--no_bits <no_bits>`          remove reads which bit code match this code. You can use [this site](https://broadinstitute.github.io/picard/explain-flags.html) to get an appropriate bit code. The default is `1540` for
   - segment unmapped
   - not passing quality controls