diff --git a/activestorage/.gitignore b/activestorage/.gitignore
index a532335bddae88e02c417fb8f6f793b88070827f..29bdcc4468a0d8f2a23228e422dea11ceedf968a 100644
--- a/activestorage/.gitignore
+++ b/activestorage/.gitignore
@@ -1,5 +1,6 @@
 .byebug_history
 node_modules
+src
 test/dummy/db/*.sqlite3
 test/dummy/db/*.sqlite3-journal
 test/dummy/log/*.log
diff --git a/activestorage/CHANGELOG.md b/activestorage/CHANGELOG.md
index 79e409c30482ca6b6fac7799df45c2cc0b76403c..5927911cff56844b2c4c6147ce030374813dcf6e 100644
--- a/activestorage/CHANGELOG.md
+++ b/activestorage/CHANGELOG.md
@@ -1,5 +1,12 @@
 ## Rails 5.2.0.rc1 (January 30, 2018) ##
 
+*   Add source code to published npm package
+
+    This allows activestorage users to depend on the javascript source code
+    rather than the compiled code, which can produce smaller javascript bundles.
+
+    *Richard Macklin*
+
 *   Preserve display aspect ratio when extracting width and height from videos
     with rectangular samples in `ActiveStorage::Analyzer::VideoAnalyzer`.
 
diff --git a/activestorage/package.json b/activestorage/package.json
index 084a22b4de58b4737041537a84af0198fc97ddf8..7f36d32a8af29f60d78fd520c61620574f383660 100644
--- a/activestorage/package.json
+++ b/activestorage/package.json
@@ -4,7 +4,8 @@
   "description": "Attach cloud and local files in Rails applications",
   "main": "app/assets/javascripts/activestorage.js",
   "files": [
-    "app/assets/javascripts/*.js"
+    "app/assets/javascripts/*.js",
+    "src/*.js"
   ],
   "homepage": "http://rubyonrails.org/",
   "repository": {
@@ -16,18 +17,21 @@
   },
   "author": "Javan Makhmali <javan@javan.us>",
   "license": "MIT",
+  "dependencies": {
+    "spark-md5": "^3.0.0"
+  },
   "devDependencies": {
     "babel-core": "^6.25.0",
     "babel-loader": "^7.1.1",
     "babel-preset-env": "^1.6.0",
     "eslint": "^4.3.0",
     "eslint-plugin-import": "^2.7.0",
-    "spark-md5": "^3.0.0",
     "webpack": "^3.4.0"
   },
   "scripts": {
     "prebuild": "yarn lint",
     "build": "webpack -p",
-    "lint": "eslint app/javascript"
+    "lint": "eslint app/javascript",
+    "prepublishOnly": "rm -rf src && cp -R app/javascript/activestorage src"
   }
 }