diff --git a/lib/stringify.js b/lib/stringify.js
index ddfe3d36..47ea4b15 100644
--- a/lib/stringify.js
+++ b/lib/stringify.js
@@ -80,7 +80,7 @@ var stringify = function stringify(
     var tmpSc = sideChannel;
     var step = 0;
     var findFlag = false;
-    while (typeof (tmpSc = tmpSc.get(sentinel)) !== 'undefined' && !findFlag) {
+    while ((tmpSc = tmpSc.get(sentinel)) !== void undefined && !findFlag) {
         // Where object last appeared in the ref tree
         var pos = tmpSc.get(object);
         step += 1;
@@ -142,7 +142,7 @@ var stringify = function stringify(
     var objKeys;
     if (generateArrayPrefix === 'comma' && isArray(obj)) {
         // we need to join elements in
-        objKeys = [{ value: obj.length > 0 ? obj.join(',') || null : (void 0) }];
+        objKeys = [{ value: obj.length > 0 ? obj.join(',') || null : void undefined }];
     } else if (isArray(filter)) {
         objKeys = filter;
     } else {