diff --git a/lib/index.js b/lib/index.js
index 4da9fc3..a1d71a6 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -17,6 +17,7 @@ module.exports = async (opts) => {
     cleanupFrames = true,
     transition = undefined,
     transitions = undefined,
+    audio = undefined,
     videos,
     output
   } = opts
@@ -58,6 +59,7 @@ module.exports = async (opts) => {
     log,
     framePattern,
     frameFormat,
+    audio,
     output,
     theme,
     onProgress: (p) => {
diff --git a/lib/transcode-video.js b/lib/transcode-video.js
index a9431f4..7d88c4c 100644
--- a/lib/transcode-video.js
+++ b/lib/transcode-video.js
@@ -6,7 +6,7 @@ const onTranscodeProgress = require('ffmpeg-on-progress')
 module.exports = async (opts) => {
   const {
     log,
-    audioPath,
+    audio,
     frameFormat,
     framePattern,
     onProgress,
@@ -30,8 +30,8 @@ module.exports = async (opts) => {
     const cmd = ffmpeg(framePattern)
       .inputOptions(inputOptions)
 
-    if (audioPath) {
-      cmd.addInput(audioPath)
+    if (audio) {
+      cmd.addInput(audio)
     }
 
     const outputOptions = []
@@ -54,7 +54,7 @@ module.exports = async (opts) => {
       ])
 
       // audio
-      .concat(!audioPath ? [ ] : [
+      .concat(!audio ? [ ] : [
         '-c:a', 'copy',
         '-shortest'
       ])
diff --git a/readme.md b/readme.md
index 77b5676..94e7315 100644
--- a/readme.md
+++ b/readme.md
@@ -174,6 +174,13 @@ const transitions = [
 ]
 ```
 
+##### audio
+
+Type: `String`
+**Required**
+
+Path or URL to an audio file to use as the audio track for the output video.
+
 ##### frameFormat
 
 Type: `string`