diff --git a/src/assets/HTMLAsset.js b/src/assets/HTMLAsset.js
index 6e73518eea2..3e4c613cea8 100644
--- a/src/assets/HTMLAsset.js
+++ b/src/assets/HTMLAsset.js
@@ -1,8 +1,7 @@
 const Asset = require('../Asset');
 const parse = require('posthtml-parser');
 const api = require('posthtml/lib/api');
-const path = require('path');
-const url = require('url');
+const urlJoin = require('../utils/urlJoin');
 const render = require('posthtml-render');
 const posthtmlTransform = require('../transforms/posthtml');
 const isURL = require('../utils/is-url');
@@ -46,12 +45,7 @@ class HTMLAsset extends Asset {
           if (elements && elements.includes(node.tag)) {
             let assetPath = this.addURLDependency(node.attrs[attr]);
             if (!isURL(assetPath)) {
-              // Use url.resolve to normalize path for windows
-              // from \path\to\res.js to /path/to/res.js
-              assetPath = url.resolve(
-                path.join(this.options.publicURL, assetPath),
-                ''
-              );
+              assetPath = urlJoin(this.options.publicURL, assetPath);
             }
             node.attrs[attr] = assetPath;
             this.isAstDirty = true;
diff --git a/src/assets/RawAsset.js b/src/assets/RawAsset.js
index a6713af8bb4..c67d240b479 100644
--- a/src/assets/RawAsset.js
+++ b/src/assets/RawAsset.js
@@ -1,20 +1,18 @@
 const Asset = require('../Asset');
-const url = require('url');
+const urlJoin = require('../utils/urlJoin');
 
 class RawAsset extends Asset {
   // Don't load raw assets. They will be copied by the RawPackager directly.
   load() {}
 
   generate() {
-    let publicURL = this.options.publicURL;
-    publicURL = /\/$/.test(publicURL) ? publicURL : `${publicURL}/`;
-
-    const pathToAsset = JSON.stringify(
-      url.resolve(publicURL, this.generateBundleName())
+    const pathToAsset = urlJoin(
+      this.options.publicURL,
+      this.generateBundleName()
     );
 
     return {
-      js: `module.exports=${pathToAsset};`
+      js: `module.exports=${JSON.stringify(pathToAsset)};`
     };
   }
 }
diff --git a/src/packagers/HTMLPackager.js b/src/packagers/HTMLPackager.js
index ac943bc3abf..6bef663e485 100644
--- a/src/packagers/HTMLPackager.js
+++ b/src/packagers/HTMLPackager.js
@@ -1,7 +1,7 @@
 const Packager = require('./Packager');
 const posthtml = require('posthtml');
 const path = require('path');
-const url = require('url');
+const urlJoin = require('../utils/urlJoin');
 
 class HTMLPackager extends Packager {
   async addAsset(asset) {
@@ -40,10 +40,7 @@ class HTMLPackager extends Packager {
         tag: 'link',
         attrs: {
           rel: 'stylesheet',
-          href: url.resolve(
-            path.join(this.options.publicURL, path.basename(bundle.name)),
-            ''
-          )
+          href: urlJoin(this.options.publicURL, path.basename(bundle.name))
         }
       });
     }
diff --git a/src/utils/urlJoin.js b/src/utils/urlJoin.js
new file mode 100644
index 00000000000..c4e169df46b
--- /dev/null
+++ b/src/utils/urlJoin.js
@@ -0,0 +1,8 @@
+const url = require('url');
+const path = require('path');
+
+module.exports = function(publicURL, assetPath) {
+  // Use url.resolve to normalize path for windows
+  // from \path\to\res.js to /path/to/res.js
+  return url.resolve(path.join(publicURL, assetPath), '');
+};