diff --git a/lib/core/index.js b/lib/core/index.js
index 920e55b9..23f273c7 100644
--- a/lib/core/index.js
+++ b/lib/core/index.js
@@ -343,11 +343,28 @@ module.exports = function createMiddleware(_dir, _options) {
       })
     }
 
+    function statWithAccess (file, cb) {
+      fs.stat(file, (err, stat) => {
+        if (err) {
+          cb(err);
+          return;
+        }
+        fs.access(file, fs.constants.R_OK, (err) => {
+          stat.readable = !err;
+          cb(err, stat);
+        });
+      });
+    }
+
 
     function statFile() {
       try {
-        fs.stat(file, (err, stat) => {
-          if (err && (err.code === 'ENOENT' || err.code === 'ENOTDIR')) {
+        statWithAccess(file, (err, stat) => {
+          const effectively404 =
+            (err && (err.code === 'ENOENT' || err.code === 'ENOTDIR')) ||
+            (!stat || !stat.readable);
+            
+          if (effectively404) {
             if (req.statusCode === 404) {
               // This means we're already trying ./404.html and can not find it.
               // So send plain text response with 404 status code