diff --git a/lib/path.js b/lib/path.js
index e278c891482070..884da4cd8e6822 100644
--- a/lib/path.js
+++ b/lib/path.js
@@ -95,7 +95,10 @@ function normalizeString(path, allowAboveRoot, separator, isPathSeparator) {
           lastSegmentLength = 2;
         }
       } else {
-        res += (res.length > 0 ? separator : '') + path.slice(lastSlash + 1, i);
+        if (res.length > 0)
+          res += `${separator}${path.slice(lastSlash + 1, i)}`;
+        else
+          res = path.slice(lastSlash + 1, i);
         lastSegmentLength = i - lastSlash - 1;
       }
       lastSlash = i;