diff --git a/build.ts b/build.ts
index eec1dc6..6726024 100644
--- a/build.ts
+++ b/build.ts
@@ -1,11 +1,14 @@
 import * as fs from 'fs-extra'
 import * as path from 'path'
+import * as util from 'util'
 import * as glob from 'glob'
 import chalk from 'chalk'
 import gzipSize from 'gzip-size'
 import brotliSize from 'brotli-size'
 import formatNumber from 'format-number'
 import { getBorderCharacters, table } from 'table'
+// @ts-ignore
+import validateHtml from 'html-tag-validator'
 
 const sourceFolder = 'src'
 const distFolder = 'dist'
@@ -41,7 +44,15 @@ async function buildAll (sourceFolder: string, distFolder: string) {
 }
 
 async function buildHtml (sourceFolder: string, distFolder: string) {
-  fs.copySync(`${sourceFolder}/index.html`, `${distFolder}/index.html`)
+  const sourceFilePath = `${sourceFolder}/index.html`
+  const sourceFileContent = fs.readFileSync(sourceFilePath, 'utf-8')
+  try {
+    const result = await util.promisify(validateHtml)(sourceFileContent)
+    console.log(result)
+    fs.copySync(sourceFilePath, `${distFolder}/index.html`)
+  } catch (e) {
+    console.error(e)
+  }
 }
 
 async function buildJavaScript (sourceFolder: string, distFolder: string) {
diff --git a/package.json b/package.json
index e223e36..506d622 100644
--- a/package.json
+++ b/package.json
@@ -21,6 +21,7 @@
     "fs-extra": "^7.0.0",
     "glob": "^7.1.2",
     "gzip-size": "^5.0.0",
+    "html-tag-validator": "^1.6.0",
     "node-sass": "^4.9.3",
     "table": "^4.0.3",
     "typescript": "^3.0.1"
diff --git a/src/index.html b/src/index.html
index 15698e0..a7e6418 100644
--- a/src/index.html
+++ b/src/index.html
@@ -11,9 +11,9 @@
     <svg width="308" height="308" xmlns="http://www.w3.org/2000/svg">
         <g fill="none" fill-rule="evenodd">
             <path d="M158.76 34.093C139.763 69.863 129 110.675 129 154s10.763 84.137 29.76 119.907c-1.579.062-3.166.093-4.76.093-66.274 0-120-53.726-120-120S87.726 34 154 34c1.594 0 3.181.031 4.76.093z"
-                  fill="currentcolor" fill-rule="nonzero" mask="url(#b)"/>
-            <circle stroke="#1e1e1e" stroke-width="6" cx="154" cy="154" r="120"/>
-            <circle stroke="#7c203a" stroke-width="6" cx="385" cy="154" r="256"/>
+                  fill="currentcolor" fill-rule="nonzero" mask="url(#b)"></path>
+            <circle stroke="#1e1e1e" stroke-width="6" cx="154" cy="154" r="120"></circle>
+            <circle stroke="#7c203a" stroke-width="6" cx="385" cy="154" r="256"></circle>
         </g>
     </svg>
     <h1>Wane</h1>
diff --git a/yarn.lock b/yarn.lock
index ec8c2fb..cba3e1b 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -470,6 +470,10 @@ hosted-git-info@^2.1.4:
   version "2.7.1"
   resolved "https://registry.yarnpkg.com/hosted-git-info/-/hosted-git-info-2.7.1.tgz#97f236977bd6e125408930ff6de3eec6281ec047"
 
+html-tag-validator@^1.6.0:
+  version "1.6.0"
+  resolved "https://registry.yarnpkg.com/html-tag-validator/-/html-tag-validator-1.6.0.tgz#ccd115ec3063595e2240985525d39732040f9b43"
+
 http-signature@~1.2.0:
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/http-signature/-/http-signature-1.2.0.tgz#9aecd925114772f3d95b65a60abb8f7c18fbace1"