diff --git a/autoprefixer/build/styles.css b/autoprefixer/build/styles.css
index be5f763..278f9c1 100644
--- a/autoprefixer/build/styles.css
+++ b/autoprefixer/build/styles.css
@@ -1,33 +1,21 @@
 .container {
-  display:-webkit-box;
-  display:-webkit-flex;
   display:-ms-flexbox;
   display:flex;
-  -webkit-box-orient:vertical;
-  -webkit-box-direction:normal;
-  -webkit-flex-direction:column;
-      -ms-flex-direction:column;
-          flex-direction:column;
-  -webkit-align-content:center;
-      -ms-flex-line-pack:center;
-          align-content:center;
-  -webkit-box-pack:center;
-  -webkit-justify-content:center;
-      -ms-flex-pack:center;
-          justify-content:center;
+  -ms-flex-direction:column;
+      flex-direction:column;
+  -ms-flex-line-pack:center;
+      align-content:center;
+  -ms-flex-pack:center;
+      justify-content:center;
 }
 
 .box1 {
-  -webkit-box-flex:10;
-  -webkit-flex:10 5 450px;
-      -ms-flex:10 5 450px;
-          flex:10 5 450px;
+  -ms-flex:10 5 450px;
+      flex:10 5 450px;
 }
 
 .box2 {
-  -webkit-box-flex:1;
-  -webkit-flex:1 1 360px;
-      -ms-flex:1 1 360px;
-          flex:1 1 360px;
+  -ms-flex:1 1 360px;
+      flex:1 1 360px;
 }
 
diff --git a/autoprefixer/gulpfile.js b/autoprefixer/gulpfile.js
index d054cba..70bdc17 100644
--- a/autoprefixer/gulpfile.js
+++ b/autoprefixer/gulpfile.js
@@ -2,13 +2,14 @@ var gulp = require('gulp');
 var autoprefixer = require('gulp-autoprefixer');
 
 
-gulp.task('styles',function() {
+gulp.task('styles',function(done) {
   gulp.src('css/styles.css')
     .pipe(autoprefixer())
-    .pipe(gulp.dest('build'))
+    .pipe(gulp.dest('build'));
+  done();
 });
 
 
 gulp.task('watch',function() {
-  gulp.watch('css/styles.css', ['styles']);
+  gulp.watch('css/styles.css', gulp.series('styles'));
 });
diff --git a/autoprefixer/package.json b/autoprefixer/package.json
index e9d7812..89cca14 100644
--- a/autoprefixer/package.json
+++ b/autoprefixer/package.json
@@ -9,7 +9,7 @@
   "author": "",
   "license": "ISC",
   "devDependencies": {
-    "gulp": "^3.9.0",
+    "gulp": "^4.0",
     "gulp-autoprefixer": "^2.3.1"
   }
 }