diff --git a/gulpfile.js b/gulpfile.js
index 1647f2ffc..a8a8425f1 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -18,9 +18,11 @@
 
 'use strict';
 
+var autoprefixer = require('autoprefixer');
 var fancylog = require('fancy-log');
 var fs = require('fs');
 var gulp = require('gulp');
+var postcss = require('gulp-postcss');
 var rename = require('gulp-rename');
 var replace = require('gulp-replace');
 var transform = require('gulp-transform');
@@ -577,6 +579,7 @@ gulp.task('generic', ['buildnumber', 'locale'], function () {
     preprocessHTML('web/viewer.html', defines)
         .pipe(gulp.dest(GENERIC_DIR + 'web')),
     preprocessCSS('web/viewer.css', 'generic', defines, true)
+        .pipe(postcss([autoprefixer()]))
         .pipe(gulp.dest(GENERIC_DIR + 'web')),
 
     gulp.src('web/compressed.tracemonkey-pldi-09.pdf')
@@ -602,6 +605,7 @@ gulp.task('components', ['buildnumber'], function () {
     createComponentsBundle(defines).pipe(gulp.dest(COMPONENTS_DIR)),
     gulp.src(COMPONENTS_IMAGES).pipe(gulp.dest(COMPONENTS_DIR + 'images')),
     preprocessCSS('web/pdf_viewer.css', 'components', defines, true)
+        .pipe(postcss([autoprefixer()]))
         .pipe(gulp.dest(COMPONENTS_DIR)),
   ]);
 });
@@ -629,6 +633,7 @@ gulp.task('minified-pre', ['buildnumber', 'locale'], function () {
     preprocessHTML('web/viewer.html', defines)
         .pipe(gulp.dest(MINIFIED_DIR + 'web')),
     preprocessCSS('web/viewer.css', 'minified', defines, true)
+        .pipe(postcss([autoprefixer()]))
         .pipe(gulp.dest(MINIFIED_DIR + 'web')),
 
     gulp.src('web/compressed.tracemonkey-pldi-09.pdf')
@@ -719,6 +724,7 @@ gulp.task('mozcentral-pre', ['buildnumber', 'locale'], function () {
     preprocessHTML('web/viewer.html', defines)
         .pipe(gulp.dest(MOZCENTRAL_CONTENT_DIR + 'web')),
     preprocessCSS('web/viewer.css', 'mozcentral', defines, true)
+        .pipe(postcss([autoprefixer()]))
         .pipe(gulp.dest(MOZCENTRAL_CONTENT_DIR + 'web')),
 
     gulp.src(FIREFOX_EXTENSION_DIR + 'locale/en-US/*.properties')
@@ -766,6 +772,7 @@ gulp.task('chromium-pre', ['buildnumber', 'locale'], function () {
     preprocessHTML('web/viewer.html', defines)
         .pipe(gulp.dest(CHROME_BUILD_CONTENT_DIR + 'web')),
     preprocessCSS('web/viewer.css', 'chrome', defines, true)
+        .pipe(postcss([autoprefixer()]))
         .pipe(gulp.dest(CHROME_BUILD_CONTENT_DIR + 'web')),
 
     gulp.src('LICENSE').pipe(gulp.dest(CHROME_BUILD_DIR)),
diff --git a/package.json b/package.json
index 5c45aa0d7..172425983 100644
--- a/package.json
+++ b/package.json
@@ -3,6 +3,7 @@
   "version": "2.0.0",
   "devDependencies": {
     "acorn": "^5.5.3",
+    "autoprefixer": "^8.2.0",
     "babel-core": "^6.26.0",
     "babel-loader": "^7.1.4",
     "babel-plugin-transform-es2015-modules-commonjs": "^6.26.0",
@@ -14,6 +15,7 @@
     "eslint-plugin-no-unsanitized": "^3.0.0",
     "fancy-log": "^1.3.2",
     "gulp": "^3.9.1",
+    "gulp-postcss": "^7.0.1",
     "gulp-rename": "^1.2.2",
     "gulp-replace": "^0.6.1",
     "gulp-transform": "^3.0.5",