Fixed as requested.

index.js

diff --git a/index.js b/index.js
index c19eb1c..83c7ea2 100644
--- a/index.js
+++ b/index.js
@@ -3,7 +3,7 @@
 const path = require('path');
 const symbols = require('./symbols')
 
-const include_dir = path.resolve(`${__dirname}/include`);
+const include_dir = path.resolve(__dirname, 'include');
 
 module.exports = {
     include_dir,