diff --git a/Makefile b/Makefile
index a048714e..74d00466 100644
--- a/Makefile
+++ b/Makefile
@@ -14,6 +14,10 @@ mac:
 	npm run package:mac
 	mv build/Whalebird-${VERSION}-mac.dmg build/Whalebird-${VERSION}-darwin-x64.dmg
 
+mas:
+	npm run build:mas
+	./appStore.sh
+
 linux:
 	npm run package:linux
 	mv build/Whalebird-${VERSION}-linux-amd64.deb build/Whalebird-${VERSION}-linux-x64.deb
diff --git a/src/main/index.ts b/src/main/index.ts
index 89d2589c..060bcd37 100644
--- a/src/main/index.ts
+++ b/src/main/index.ts
@@ -74,23 +74,28 @@ let mainWindow: BrowserWindow | null
 let tray: Tray | null
 const winURL = process.env.NODE_ENV === 'development' ? `http://localhost:9080` : `file://${__dirname}/index.html`
 
-// Enforces single instance for linux and windows.
-const gotTheLock = app.requestSingleInstanceLock()
+// MAS build is not allowed requestSingleInstanceLock.
+// ref: https://github.com/h3poteto/whalebird-desktop/issues/1030
+// ref: https://github.com/electron/electron-osx-sign/issues/137#issuecomment-307626305
+if (process.platform !== 'darwin') {
+  // Enforces single instance for linux and windows.
+  const gotTheLock = app.requestSingleInstanceLock()
 
-if (!gotTheLock) {
-  app.quit()
-} else {
-  app.on('second-instance', () => {
-    // Someone tried to run a second instance, we should focus our window.
-    if (mainWindow) {
-      if (mainWindow.isMinimized()) mainWindow.restore()
-      if (!mainWindow!.isVisible()) {
-        mainWindow!.show()
-        mainWindow!.setSkipTaskbar(false)
+  if (!gotTheLock) {
+    app.quit()
+  } else {
+    app.on('second-instance', () => {
+      // Someone tried to run a second instance, we should focus our window.
+      if (mainWindow) {
+        if (mainWindow.isMinimized()) mainWindow.restore()
+        if (!mainWindow!.isVisible()) {
+          mainWindow!.show()
+          mainWindow!.setSkipTaskbar(false)
+        }
+        mainWindow.focus()
       }
-      mainWindow.focus()
-    }
-  })
+    })
+  }
 }
 
 const appId = pkg.build.appId