diff --git a/README.md b/README.md
index 15f7127..cb021f6 100644
--- a/README.md
+++ b/README.md
@@ -35,7 +35,8 @@ docker run --detach --volume $(pwd):/data --env PFSENSE_USER=backupuser --env PF
 - `PFSENSE_CRON_SCHEDULE` Optional. The cron schedule to use, should contain 5 items separated by spaces. This parameter is not validated. No default.
 - `PFSENSE_BACK_UP_RRD_DATA`. Optional. Should be either 1 or 0. This parameters is not validated. Include RRD data in the backup? 1=yes, 0=no. Default=1.
 - `PFSENSE_BACKUP_DESTINATION_DIR`. Optional. What is the destination directory to back up to. This directory must exist and be writable. Default=/data
-- `TZ`. Optional. Timezone settings 
+- `TZ`. Optional. Timezone settings
+- `keepfiles` . Optional. How many Files to be keep
 
 ## Help!
 - Is the username correct?