diff --git a/Gemfile b/Gemfile
index 77b86575..a041e435 100644
--- a/Gemfile
+++ b/Gemfile
@@ -6,7 +6,7 @@ git_source(:github) { |repo| "https://github.com/#{repo}.git" }
 ruby "3.3.4"
 
 gem "react_on_rails", "16.1.1"
-gem "shakapacker", "8.2.0"
+gem "shakapacker", "9.0.0.beta.5"
 
 # Bundle edge Rails instead: gem "rails", github: "rails/rails"
 gem "listen"
diff --git a/Gemfile.lock b/Gemfile.lock
index b0cddd1d..13a035f7 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -390,7 +390,7 @@ GEM
       websocket (~> 1.0)
     semantic_range (3.1.0)
     sexp_processor (4.17.1)
-    shakapacker (8.2.0)
+    shakapacker (9.0.0.beta.5)
       activesupport (>= 5.2)
       package_json
       rack-proxy (>= 0.6.1)
@@ -499,7 +499,7 @@ DEPENDENCIES
   scss_lint
   sdoc
   selenium-webdriver (~> 4)
-  shakapacker (= 8.2.0)
+  shakapacker (= 9.0.0.beta.5)
   spring
   spring-commands-rspec
   stimulus-rails (~> 1.3)
diff --git a/SHAKAPACKER_BETA5_ISSUE.md b/SHAKAPACKER_BETA5_ISSUE.md
new file mode 100644
index 00000000..2689f2e4
--- /dev/null
+++ b/SHAKAPACKER_BETA5_ISSUE.md
@@ -0,0 +1,80 @@
+# Shakapacker 9.0.0-beta.5 Missing Compiled JavaScript Files
+
+## Issue Summary
+Shakapacker 9.0.0-beta.5 npm package is published with TypeScript source files (.ts) but missing the compiled JavaScript files (.js), making the package unusable.
+
+## Details
+
+### What's happening:
+When trying to use shakapacker 9.0.0-beta.5, webpack fails with:
+```
+Error: Cannot find module '/path/to/node_modules/shakapacker/package/index.js'
+```
+
+### Root Cause:
+The npm package contains only TypeScript source files without the compiled JavaScript output.
+
+### Investigation Results:
+
+**Beta.4 package structure (working):**
+```bash
+$ ls -la node_modules/shakapacker/package/
+-rw-r--r--  config.js      # ✅ JavaScript file exists
+-rw-r--r--  dev_server.js  # ✅ JavaScript file exists  
+-rw-r--r--  env.js         # ✅ JavaScript file exists
+-rw-r--r--  index.js       # ✅ JavaScript file exists
+-rw-r--r--  index.d.ts     # TypeScript definitions
+```
+
+**Beta.5 package structure (broken):**
+```bash
+$ ls -la node_modules/shakapacker/package/
+-rw-r--r--  config.ts      # ❌ TypeScript source only
+-rw-r--r--  dev_server.ts  # ❌ TypeScript source only
+-rw-r--r--  env.ts         # ❌ TypeScript source only
+-rw-r--r--  index.ts       # ❌ TypeScript source only
+-rw-r--r--  index.d.ts     # TypeScript definitions
+# Missing: index.js, config.js, dev_server.js, env.js
+```
+
+### Package.json has build script:
+```json
+{
+  "scripts": {
+    "build": "tsc",
+    // ...
+  }
+}
+```
+
+But the tsconfig.json is not included in the published package, and the build output is missing.
+
+## Likely Fix Needed
+
+The build process needs to:
+1. Run `npm run build` before publishing to compile TypeScript to JavaScript
+2. Ensure the compiled .js files are included in the npm package
+3. Update the package.json "files" field or .npmignore to include the compiled output
+
+## Workaround
+
+For now, users should use:
+- **9.0.0-beta.4** which has the compiled JavaScript files
+- Set `javascript_transpiler: babel` in shakapacker.yml (beta.4 defaults to SWC)
+
+## Version Comparison
+
+| Version | Status | Notes |
+|---------|--------|-------|
+| 8.2.0 | ✅ Working | Stable release |
+| 8.4.0 | ✅ Working | Latest stable |
+| 9.0.0-beta.4 | ✅ Working | Has compiled JS, defaults to SWC |
+| 9.0.0-beta.5 | ❌ Broken | Missing compiled JS files |
+
+## Configuration Change for Beta.4
+
+When using beta.4, add to `config/shakapacker.yml`:
+```yaml
+default: &default
+  javascript_transpiler: babel  # Beta versions default to SWC
+```
\ No newline at end of file
diff --git a/config/shakapacker.yml b/config/shakapacker.yml
index ebc5e4c5..a4d453f2 100644
--- a/config/shakapacker.yml
+++ b/config/shakapacker.yml
@@ -8,6 +8,7 @@ default: &default
   cache_path: tmp/shakapacker
   webpack_compile_output: true
   nested_entries: true
+  javascript_transpiler: babel
 
   # Additional paths webpack should lookup modules
   # ['app/assets', 'engine/foo/app/assets']
diff --git a/package.json b/package.json
index afa73247..7ba7194d 100644
--- a/package.json
+++ b/package.json
@@ -93,7 +93,7 @@
     "sass": "^1.58.3",
     "sass-loader": "^13.3.2",
     "sass-resources-loader": "^2.2.5",
-    "shakapacker": "8.2.0",
+    "shakapacker": "9.0.0-beta.5",
     "stimulus": "^3.0.1",
     "style-loader": "^3.3.1",
     "tailwindcss": "^3.3.3",
diff --git a/yarn.lock b/yarn.lock
index 0189edd8..1fafbc16 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -8263,10 +8263,10 @@ setprototypeof@1.2.0:
   resolved "https://registry.npmjs.org/setprototypeof/-/setprototypeof-1.2.0.tgz#66c9a24a73f9fc28cbe66b09fed3d33dcaf1b424"
   integrity sha512-E5LDX7Wrp85Kil5bhZv46j8jOeboKq5JMmYM3gVGdGH8xFpPWXUMsNrlODCrkoxMEeNi/XZIwuRvY4XNwYMJpw==
 
-shakapacker@8.2.0:
-  version "8.2.0"
-  resolved "https://registry.npmjs.org/shakapacker/-/shakapacker-8.2.0.tgz#c7bed87b8be2ae565cfe616f68552be545c77e14"
-  integrity sha512-Ct7BFqJVnKbxdqCzG+ja7Q6LPt/PlB7sSVBfG5jsAvmVCADM05cuoNwEgYNjFGKbDzHAxUqy5XgoI9Y030+JKQ==
+shakapacker@9.0.0-beta.5:
+  version "9.0.0-beta.5"
+  resolved "https://registry.npmjs.org/shakapacker/-/shakapacker-9.0.0-beta.5.tgz#1fa7c9641f89f3abcad507f4c077508730da1ece"
+  integrity sha512-L0jEx1yFUxlpUcygceQFMFl7qYjgk4OB453KnKFa8EqJ5zjmDXTkHUDjMuzGQDT+l/oHeaX5jAg2HpkvM5P93A==
   dependencies:
     js-yaml "^4.1.0"
     path-complete-extname "^1.0.0"