diff --git a/lib/path.js b/lib/path.js
index 658b5d6901df..470ae54b3fca 100644
--- a/lib/path.js
+++ b/lib/path.js
@@ -1295,6 +1295,12 @@ const posix = {
     if (path.length === 0)
       return '.';
 
+    // Already normalized: no '.' / '..' segments and no empty '//' segments.
+    if (StringPrototypeIndexOf(path, '.') === -1 &&
+        StringPrototypeIndexOf(path, '//') === -1) {
+      return path;
+    }
+
     const isAbsolute = path[0] === '/';
     const trailingSeparator = path[path.length - 1] === '/';