diff --git a/src/extension-support/extension-manager.js b/src/extension-support/extension-manager.js
index 938e791dc..c3346a22d 100644
--- a/src/extension-support/extension-manager.js
+++ b/src/extension-support/extension-manager.js
@@ -8,7 +8,7 @@ const BlockType = require('./block-type');
 // TODO: change extension spec so that library info, including extension ID, can be collected through static methods
 const Scratch3PenBlocks = require('../blocks/scratch3_pen');
 const Scratch3WeDo2Blocks = require('../blocks/scratch3_wedo2');
-const Scratch3MusicBlocks = require('../blocks/scratch3_music');
+const Scratch3MusicBlocks = require('../extensions/scratch3_music');
 const builtinExtensions = {
     pen: Scratch3PenBlocks,
     wedo2: Scratch3WeDo2Blocks,
diff --git a/src/blocks/scratch3_music.js b/src/extensions/scratch3_music/index.js
similarity index 97%
rename from src/blocks/scratch3_music.js
rename to src/extensions/scratch3_music/index.js
index 5cccaf278..ba1360034 100644
--- a/src/blocks/scratch3_music.js
+++ b/src/extensions/scratch3_music/index.js
@@ -1,9 +1,9 @@
-const ArgumentType = require('../extension-support/argument-type');
-const BlockType = require('../extension-support/block-type');
-const Clone = require('../util/clone');
-const Cast = require('../util/cast');
-const MathUtil = require('../util/math-util');
-const Timer = require('../util/timer');
+const ArgumentType = require('../../extension-support/argument-type');
+const BlockType = require('../../extension-support/block-type');
+const Clone = require('../../util/clone');
+const Cast = require('../../util/cast');
+const MathUtil = require('../../util/math-util');
+const Timer = require('../../util/timer');
 
 /**
  * An array of drum names, used in the play drum block.