diff --git a/lib/querystring.js b/lib/querystring.js
index efd2969229..f48ee5802f 100644
--- a/lib/querystring.js
+++ b/lib/querystring.js
@@ -29,21 +29,22 @@ QueryString.stringify = QueryString.encode = function (obj, sep, eq, munge, name
   munge = typeof munge == "undefined" || munge;
   sep = sep || "&";
   eq = eq || "=";
-  if (obj == null || typeof obj == "function") {
+  var type = Object.prototype.toString.call(obj);
+  if (obj == null || type == "[object Function]" || type == "[object Number]" && !isFinite(obj)) {
     return name ? QueryString.escape(name) + eq : "";
   }
 
-  if (isBool(obj)) {
-    obj = +obj;
-  }
-  if (isNumber(obj) || isString(obj)) {
-    return QueryString.escape(name) + eq + QueryString.escape(obj);
-  }
-  if (isA(obj, [])) {
-    name = name + (munge ? "[]" : "");
-    return obj.map(function (item) {
-      return QueryString.stringify(item, sep, eq, munge, name);
-    }).join(sep);
+  switch (type) {
+    case '[object Boolean]':
+      obj = +obj; // fall through
+    case '[object Number]':
+    case '[object String]':
+      return QueryString.escape(name) + eq + QueryString.escape(obj);
+    case '[object Array]':
+      name = name + (munge ? "[]" : "");
+      return obj.map(function (item) {
+        return QueryString.stringify(item, sep, eq, munge, name);
+      }).join(sep);
   }
   // now we know it's an object.
 
@@ -109,20 +110,3 @@ QueryString.parse = QueryString.decode = function (qs, sep, eq) {
   });
   return obj;
 };
-
-function isA (thing, canon) {
-  // special case for null and undefined
-  if (thing == null || canon == null) {
-    return thing === canon;
-  }
-  return Object.getPrototypeOf(Object(thing)) == Object.getPrototypeOf(Object(canon));
-}
-function isBool (thing) {
-  return isA(thing, true);
-}
-function isNumber (thing) {
-  return isA(thing, 0) && isFinite(thing);
-}
-function isString (thing) {
-  return isA(thing, "");
-}
\ No newline at end of file
diff --git a/test/simple/test-querystring.js b/test/simple/test-querystring.js
index 961c1ec35e..40f68d83da 100644
--- a/test/simple/test-querystring.js
+++ b/test/simple/test-querystring.js
@@ -67,17 +67,24 @@ var qsWeirdObjects = [
   [ {d:Date}, "d=", {"d":""} ],
   [ {f:new Boolean(false), t:new Boolean(true)}, "f=0&t=1", {"f":0, "t":1} ],
   [ {f:false, t:true}, "f=0&t=1", {"f":0, "t":1} ],
+  [ {n:null}, "n=", {"n":""} ],
+  [ {nan:NaN}, "nan=", {"nan":""} ],
+  [ {inf:Infinity}, "inf=", {"inf":""} ]
 ];
 }
 
+var Script = process.binding('evals').Script;
+var foreignObject = Script.runInContext('({"foo": ["bar", "baz"]})', Script.createContext());
+
 var qsNoMungeTestCases = [
   ["", {}],
   ["foo=bar&foo=baz", {"foo": ["bar", "baz"]}],
+  ["foo=bar&foo=baz", foreignObject],
   ["blah=burp", {"blah": "burp"}],
   ["gragh=1&gragh=3&goo=2", {"gragh": ["1", "3"], "goo": "2"}],
   ["frappucino=muffin&goat%5B%5D=scone&pond=moose",
    {"frappucino": "muffin", "goat[]": "scone", "pond": "moose"}],
-  ["obj%5Btrololol%5D=yes&obj%5Blololo%5D=no", {"obj": {"trololol": "yes", "lololo": "no"}}],
+  ["obj%5Btrololol%5D=yes&obj%5Blololo%5D=no", {"obj": {"trololol": "yes", "lololo": "no"}}]
 ];
 
 // test that the canonical qs is parsed properly.