diff --git a/node_modules/vfs-socket/worker.js b/node_modules/vfs-socket/worker.js
index fbf197a3..8cf0d3f4 100644
--- a/node_modules/vfs-socket/worker.js
+++ b/node_modules/vfs-socket/worker.js
@@ -437,6 +437,8 @@ function Worker(vfs) {
         var keys = Object.keys(meta || {});
         for (var i = 0, l = keys.length; i < l; i++) {
             var key = keys[i];
+            if (!meta[key])
+                continue;
             switch (key) {
                 case "stream": token.stream = storeStream(meta.stream); break;
                 case "process": token.process = storeProcess(meta.process); break;