diff --git a/README.md b/README.md
index 62cf9e8..d1256a7 100644
--- a/README.md
+++ b/README.md
@@ -16,13 +16,14 @@ ____
 >
 > * privileged rights
 > * [Python 3](https://www.python.org/downloads/) (tested version 3.9.5 on [Debian GNU/Linux 11](http://ftp.debian.org/debian/dists/bullseye/))
+> * [cryptography](https://cryptography.io/) Python 3 module (tested version 41.0.1)
 > * Existing `status`, `server`, `ca`, `cert` options in [server.conf](https://openvpn.net/community-resources/reference-manual-for-openvpn-2-5/#options)
 
-|  POSITION | PARAMETERS   |       DESCRIPTION      |    DEFAULT    |
-|-----------|--------------|------------------------|---------------|
+| PARAMETERS   |       DESCRIPTION      |    DEFAULT    |
+|--------------|------------------------|---------------|
 |**[-s, --server_conf]**|path to OpenVPN server configuration file|**REQUIRED**|
 |**[-f, --filter]**|client names filter by regex|`.*`|
-|**[-g, --geo]**|check client real ip geo location (may be slow)|`.*`|
+|**[-g, --geo]**|check client real ip geo location (may be slow)|`None`|
 
 Example usage with Zabbix agent:  
 
@@ -39,6 +40,8 @@ sudo systemctl restart openvpn@server
 ```
 
 ```bash
+# install dependencies
+sudo pip install cryptography
 # download
 sudo wget https://git.hmp.today/pavel.muhortov/openvpn-management/raw/branch/master/ovpn_status.py -O /etc/openvpn/server/ovpn_status.py
 sudo chmod +x /etc/openvpn/server/ovpn_status.py