diff --git a/lib/utils.js b/lib/utils.js
index d6faf6dfd8..86ba8f0376 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -528,8 +528,10 @@ exports.canonicalize = function canonicalize(value, stack, typeHint) {
  * hasMatchingExtname('foo.html', ['js', 'css']); // => false
  */
 function hasMatchingExtname(pathname, exts) {
-  var re = new RegExp('\\.(?:' + exts.join('|') + ')$');
-  return re.test(path.extname(pathname));
+  var suffix = path.extname(pathname).slice(1);
+  return exts.some(function(element) {
+    return suffix === element;
+  });
 }
 
 /**