diff --git a/lib/gen-id.js b/lib/gen-id.js
index 1e3bd10..ce9f887 100644
--- a/lib/gen-id.js
+++ b/lib/gen-id.js
@@ -1,6 +1,12 @@
-const idRegistory = Object.create(null)
-let uid = 0
+// borrowed from vue-loader
+const path = require('path')
+const hash = require('hash-sum')
+const cache = Object.create(null)
+const sepRE = new RegExp(path.sep.replace('\\', '\\\\'), 'g')
 
-module.exports = filePath => {
-  return idRegistory[filePath] || (idRegistory[filePath] = ++uid)
+module.exports = function genId (file, context) {
+  const contextPath = context.split(path.sep)
+  const rootId = contextPath[contextPath.length - 1]
+  file = rootId + '/' + path.relative(context, file).replace(sepRE, '/')
+  return cache[file] || (cache[file] = hash(file))
 }
diff --git a/lib/index.js b/lib/index.js
index a52f2d9..865b5ff 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -7,7 +7,7 @@ const sourceMap = require('source-map')
 const SourceMapConsumer = sourceMap.SourceMapConsumer
 
 module.exports = function(contents, sourcemap) {
-  const id = genId(this.resourcePath)
+  const id = genId(this.resourcePath, process.cwd())
   let hasComponent = false
 
   const parseOptions = { sourceType: 'module' }
diff --git a/test/specs/index.spec.js b/test/specs/index.spec.js
index 71e0e17..cbe6b80 100644
--- a/test/specs/index.spec.js
+++ b/test/specs/index.spec.js
@@ -1,9 +1,19 @@
 const path = require('path')
 const fs = require('fs')
-const DefaultLoader = require('../../lib/index')
+const loader = require('../../lib/index')
 
-class Loader extends DefaultLoader {
-  callback(err, contents, sourcemap) { this.callbackAnswer = { err, contents, sourcemap } }
+function loadCode(data) {
+  let callbackAnswer
+
+  loader.call({
+    resourcePath: '/path/to/test.html',
+    options: {},
+    callback: (err, contents, sourcemap) => {
+      callbackAnswer = { err, contents, sourcemap }
+    }
+  }, data)
+
+  return callbackAnswer
 }
 
 function test (name) {
@@ -11,8 +21,8 @@ function test (name) {
   const expected = fs.readFileSync(path.resolve(__dirname, '../expects', name), 'utf8')
 
   it(name, () => {
-    const loader = new Loader(src)
-    expect(loader.callbackAnswer.contents.replace(/if \(module\.hot\)[\s\S]*$/, '').trim()).toBe(expected.trim())
+    const callbackAnswer = loadCode(src)
+    expect(callbackAnswer.contents.replace(/if \(module\.hot\)[\s\S]*$/, '').trim()).toBe(expected.trim())
   })
 }