diff --git a/README.md b/README.md
index 30a7869..7f61f7d 100644
--- a/README.md
+++ b/README.md
@@ -7,3 +7,5 @@ git clone https://gitea.arnweb.nl/corner/Cassettea-api-node.git && cd Cassettea-
 npm install
 DEBUG=Cassettea-api-node:* npm start
 ```
+
+Also make sure that you have a [ffmpeg](https://ffmpeg.org) executable file in `bin/ffmpeg`. Without this, the audio downloader will _not_ work.