diff --git a/.github/workflows/compatibility.yml b/.github/workflows/compatibility.yml
new file mode 100644
index 000000000..17b257cfd
--- /dev/null
+++ b/.github/workflows/compatibility.yml
@@ -0,0 +1,23 @@
+name: Check compatibility
+on:
+  pull_request:
+  push:
+    branches: [master]
+jobs:
+  test:
+    name: Check source code compatibility
+    runs-on: Ubuntu-18.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@master
+        with:
+          fetch-depth: 1
+      - name: Run Test
+        run: |
+          git clone https://github.com/kylef/swiftenv.git ~/.swiftenv
+          export SWIFTENV_ROOT="$HOME/.swiftenv"
+          export PATH="$SWIFTENV_ROOT/bin:$PATH"
+          eval "$(swiftenv init -)"
+          make bootstrap
+          cd Example
+          swift build --triple wasm32-unknonw-wasi
diff --git a/Example/JavaScriptKitExample/Sources/JavaScriptKitExample/main.swift b/Example/JavaScriptKitExample/Sources/JavaScriptKitExample/main.swift
index 2ddec8ad4..58f582a7e 100644
--- a/Example/JavaScriptKitExample/Sources/JavaScriptKitExample/main.swift
+++ b/Example/JavaScriptKitExample/Sources/JavaScriptKitExample/main.swift
@@ -1,17 +1,17 @@
 import JavaScriptKit
 
-let alert = JSObjectRef.global.alert.function!
-let document = JSObjectRef.global.document.object!
+let alert = JSObject.global.alert.function!
+let document = JSObject.global.document
 
-let divElement = document.createElement!("div").object!
+var divElement = document.createElement("div")
 divElement.innerText = "Hello, world"
-let body = document.body.object!
-_ = body.appendChild!(divElement)
+_ = document.body.appendChild(divElement)
 
-let buttonElement = document.createElement!("button").object!
+var buttonElement = document.createElement("button")
 buttonElement.innerText = "Click me!"
-buttonElement.onclick = .function { _ in
+let listener = JSClosure { _ in
     alert("Swift is running on browser!")
 }
+buttonElement.onclick = .function(listener)
 
-_ = body.appendChild!(buttonElement)
+_ = document.body.appendChild(buttonElement)