diff --git a/README.md b/README.md
index 3283a6e..0225522 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,8 @@ Your SIP PBX should be comaptible with `L16@48000` or `OPUS@48000` voice codec.
 
 ## Usage
 
-1. [Download](https://ci.appveyor.com/api/projects/Infactum/tg2sip/artifacts/tg2sip.zip?branch=master) prebuild version from CI or compile it yourself.
+1. [Download](https://ci.appveyor.com/api/projects/Infactum/tg2sip/artifacts/tg2sip.zip?branch=master) prebuild version from CI or compile it yourself.  
+Prebuild binaries have been tested in Ubuntu 18.04 Bionic and require `libopus0` package installed.
 2. Obtain `api_id` and `api_hash` tokens from [this](https://my.telegram.org) page and put them in `settings.ini` file.
 3. Login into telegram with `gen_db` app
 4. Set SIP server settings in `settings.ini`