diff --git a/lib/build.js b/lib/build.js
index 149f9f93a0..44c6585e3e 100644
--- a/lib/build.js
+++ b/lib/build.js
@@ -63,12 +63,22 @@ module.exports = async function build (sourceDir, cliOptions = {}) {
     .map(renderHeadTag)
     .join('\n  ')
 
-  // render pages
   console.log('Rendering static HTML...')
+
+  // render pages from md files
   for (const page of options.siteData.pages) {
     await renderPage(page)
   }
 
+  // render extra pages
+  const extraPages = [
+    ...(options.siteConfig.themeConfig.extraPages || []),
+    ...(options.siteConfig.extraPages || [])
+  ]
+  for (const path of extraPages) {
+    await renderPage({ path })
+  }
+
   // if the user does not have a custom 404.md, generate the theme's default
   if (!options.siteData.pages.some(p => p.path === '/404.html')) {
     await renderPage({ path: '/404.html' })
@@ -153,7 +163,7 @@ module.exports = async function build (sourceDir, cliOptions = {}) {
       console.error(chalk.red(`Error rendering ${pagePath}:`))
       throw e
     }
-    const filename = pagePath.replace(/\/$/, '/index.html').replace(/^\//, '')
+    const filename = pagePath.replace(/(\/$)|((?<!(.html))$)/, '/index.html').replace(/^\//, '')
     const filePath = path.resolve(outDir, filename)
     await fs.ensureDir(path.dirname(filePath))
     await fs.writeFile(filePath, html)
diff --git a/lib/prepare.js b/lib/prepare.js
index e892f1cbcc..1ed3d57c4f 100644
--- a/lib/prepare.js
+++ b/lib/prepare.js
@@ -71,21 +71,7 @@ if (!Object.assign) Object.assign = require('object-assign')`
 
 async function resolveOptions (sourceDir) {
   const vuepressDir = path.resolve(sourceDir, '.vuepress')
-  const configPath = path.resolve(vuepressDir, 'config.js')
-  const configYmlPath = path.resolve(vuepressDir, 'config.yml')
-  const configTomlPath = path.resolve(vuepressDir, 'config.toml')
-
-  delete require.cache[configPath]
-
-  // resolve siteConfig
-  let siteConfig = {}
-  if (fs.existsSync(configYmlPath)) {
-    siteConfig = await parseConfig(configYmlPath)
-  } else if (fs.existsSync(configTomlPath)) {
-    siteConfig = await parseConfig(configTomlPath)
-  } else if (fs.existsSync(configPath)) {
-    siteConfig = require(configPath)
-  }
+  const siteConfig = await resolveConfig(vuepressDir)
 
   // normalize head tag urls for base
   const base = siteConfig.base || '/'
@@ -159,9 +145,12 @@ async function resolveOptions (sourceDir) {
       themeEnhanceAppPath = null
     }
   }
+  // resolve theme default config
+  const themeDefaultConfig = await resolveConfig(themePath)
 
   // resolve theme config
-  const themeConfig = siteConfig.themeConfig || {}
+  const themeConfig = Object.assign({}, themeDefaultConfig, siteConfig.themeConfig || {})
+  siteConfig.themeConfig = themeConfig
 
   // resolve algolia
   const isAlgoliaSearch = (
@@ -335,6 +324,29 @@ function sort (arr) {
   })
 }
 
+async function resolveConfig (dir) {
+  const configPath = path.resolve(dir, 'config.js')
+  const configYmlPath = path.resolve(dir, 'config.yml')
+  const configTomlPath = path.resolve(dir, 'config.toml')
+
+  delete require.cache[configPath]
+
+  // resolve siteConfig
+  if (fs.existsSync(configPath)) {
+    return require(configPath)
+  }
+
+  if (fs.existsSync(configYmlPath)) {
+    return await parseConfig(configYmlPath)
+  }
+
+  if (fs.existsSync(configTomlPath)) {
+    return await parseConfig(configTomlPath)
+  }
+
+  return {}
+}
+
 async function parseConfig (file) {
   const content = await fs.readFile(file, 'utf-8')
   const [extension] = /.\w+$/.exec(file)