diff --git a/lib/fs.js b/lib/fs.js
index bd027c3427..c4f7d70617 100644
--- a/lib/fs.js
+++ b/lib/fs.js
@@ -1528,6 +1528,7 @@ fs.realpathSync = function realpathSync(p, options) {
       var stat = fs.lstatSync(base);
       if (!stat.isSymbolicLink()) {
         knownHard[base] = true;
+        if (cache) cache.set(base, base);
         continue;
       }