diff --git a/web/download.html b/web/download.html
index 3fb9da13..1f5a2f72 100644
--- a/web/download.html
+++ b/web/download.html
@@ -61,6 +61,7 @@
 			<li><a href="https://cmake.org/">Cmake is required to build from source.</a></li>
 			<li>Cross platform Qt GUI replaces deprecated GTK GUI</li>
 			<li>Requires Qt5, SDL2, minizip, zlib, and OpenGL</li>
+			<li>ffmpeg libraries (libavutil, libavformat, libavcodec, libswscale, libswresample) are recommended optional dependencies that provide many encoding features for AVI recording</li>
 			<li>libx264 is an optional dependency that provides H.264 video encoding for AVI recording</li>
 			<li>Lua 5.1 is optional, if the system cannot provide this, an internal version of Lua will be statically linked</li>
 			<li>The Qt GUI is required and will automatically be part of the build.</li>
diff --git a/web/osx.html b/web/osx.html
index 535cf77e..e030a0ac 100644
--- a/web/osx.html
+++ b/web/osx.html
@@ -81,7 +81,8 @@
 		 brew install qt5
 		 brew install sdl2
 		 brew install minizip
-		 brew install x264  (optional dependency but recommended for AVI recording)
+		 brew install ffmpeg (optional dependency but recommended for AVI recording)
+		 brew install x264   (optional dependency but recommended for AVI recording)
 		 </pre>
 		 Otherwise you can install the dmg packages available from the Qt and SDL websites. 
 		 <br><br>The following tools are required to build from source: