diff --git a/lib/utils.js b/lib/utils.js
deleted file mode 100644
index eb10ca45..00000000
--- a/lib/utils.js
+++ /dev/null
@@ -1,35 +0,0 @@
-'use strict'
-const fs = require('fs')
-const path = require('path')
-const bodyParser = require('body-parser')
-const mime = require('mime-types')
-
-exports.isSQLite = function isSQLite (sequelize) {
-  return sequelize.options.dialect === 'sqlite'
-}
-
-exports.getImageMimeType = function getImageMimeType (imagePath) {
-  return mime.lookup(path.extname(imagePath))
-}
-
-exports.isRevealTheme = function isRevealTheme (theme) {
-  if (fs.existsSync(path.join(__dirname, '..', 'public', 'build', 'reveal.js', 'css', 'theme', theme + '.css'))) {
-    return theme
-  }
-  return undefined
-}
-
-exports.wrap = innerHandler => (req, res, next) => innerHandler(req, res).catch(err => next(err))
-
-// create application/x-www-form-urlencoded parser
-exports.urlencodedParser = bodyParser.urlencoded({
-  extended: false,
-  limit: 1024 * 1024 * 10 // 10 mb
-})
-
-// create text/markdown parser
-exports.markdownParser = bodyParser.text({
-  inflate: true,
-  type: ['text/plain', 'text/markdown'],
-  limit: 1024 * 1024 * 10 // 10 mb
-})
diff --git a/lib/utils.ts b/lib/utils.ts
new file mode 100644
index 00000000..17fea0af
--- /dev/null
+++ b/lib/utils.ts
@@ -0,0 +1,37 @@
+import * as fs from "fs";
+import * as path from "path";
+
+import * as mime from "mime-types";
+import * as bodyParser from "body-parser";
+
+export function isSQLite(sequelize) {
+  return sequelize.options.dialect === 'sqlite'
+}
+
+export function getImageMimeType(imagePath) {
+  return mime.lookup(path.extname(imagePath))
+}
+
+export function isRevealTheme(theme) {
+  if (fs.existsSync(path.join(__dirname, '..', 'public', 'build', 'reveal.js', 'css', 'theme', theme + '.css'))) {
+    return theme
+  }
+  return undefined
+}
+
+export function wrap(innerHandler) {
+  return (req, res, next) => innerHandler(req, res).catch(err => next(err))
+}
+
+// create application/x-www-form-urlencoded parser
+export const urlencodedParser = bodyParser.urlencoded({
+  extended: false,
+  limit: 1024 * 1024 * 10 // 10 mb
+})
+
+// create text/markdown parser
+export const markdownParser = bodyParser.text({
+  inflate: true,
+  type: ['text/plain', 'text/markdown'],
+  limit: 1024 * 1024 * 10 // 10 mb
+})