diff --git a/dc09.js b/dc09.js
index e837d52..7f4876a 100644
--- a/dc09.js
+++ b/dc09.js
@@ -12,6 +12,7 @@ const exec = (cmd) => {
         console.log(`Exec: ${cmd}`)
     return cp.execSync(cmd)
 }
+const cwd = process.cwd()
 
 const CleanCSS = require('clean-css')
 const Handlebars = require('handlebars')
@@ -38,6 +39,18 @@ main()
 function main() {
     switch (process.argv[2]) {
 
+        case 'watch':
+            fs.watch(cwd, {recursive: true}, (_ev, file) => {
+                const rel = path.relative(cwd, file)
+                if (rel.includes('dist/'))
+                    return
+                print(`Changed: ${file}`, true, '#', yellow)
+                const dirs = rel.split(path.sep)
+                const dir = (dirs.length > 1) ? dirs[0] : '.'
+                buildOne(dir)
+            })
+            break
+
         case 'build':
             const dir = process.argv[3]
             if (dir)
@@ -57,6 +70,7 @@ function main() {
         default:
             print('Available actions:', true)
             printList([
+                'watch',
                 'build',
                 'build <dir>',
                 'archive',