diff --git a/README.md b/README.md
index 35f4178..4128721 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@ Most features are optional and can easily be disabled!
 * Extract single images from albums
 
 ### Supported hosts
-* Reddit text/self, images and videos
+* Reddit text/self, images and videos[\*](#reddit-videos)
 * Imgur
 * Gfycat
 * Eroshare archive
@@ -44,6 +44,9 @@ reddit-post-dump requires a arbitrarily recent version of Node.js. Before use, d
 * `node app.js --user=ThePendulum`
 * `node app.js --user=ThePendulum --limit=10 --sort=top`
 
+### \*Reddit videos
+The audio stream for reddit videos (that have audio) is hosted separately, and will be saved as such (typically {filename}-0 and {filename}-1). For them to be muxed into a single file automatically, **ffmpeg must be available on the system**, and the separate source files will be deleted when muxing has succeeded. If ffmpeg is not available, the separate files will remain as is.
+
 ## Configuration
 The default configuration aims to be sensible, and the application may be used without any further tweaking. However, a multitude of options make this utility particularly powerful.