diff --git a/underscore.js b/underscore.js
index 1efa346b5..d36e07552 100644
--- a/underscore.js
+++ b/underscore.js
@@ -1110,11 +1110,6 @@
 
   // Internal recursive comparison function for `isEqual`.
   var eq = function(a, b, aStack, bStack) {
-    // Identical objects are equal. `0 === -0`, but they aren't identical.
-    // See the [Harmony `egal` proposal](http://wiki.ecmascript.org/doku.php?id=harmony:egal).
-    if (a === b) return a !== 0 || 1 / a === 1 / b;
-    // A strict comparison is necessary because `null == undefined`.
-    if (a == null || b == null) return a === b;
     // Unwrap any wrapped objects.
     if (a instanceof _) a = a._wrapped;
     if (b instanceof _) b = b._wrapped;
@@ -1203,7 +1198,13 @@
 
   // Perform a deep comparison to check if two objects are equal.
   _.isEqual = function(a, b) {
-    return eq(a, b);
+      // Identical objects are equal. `0 === -0`, but they aren't identical.
+      // See the [Harmony `egal` proposal](http://wiki.ecmascript.org/doku.php?id=harmony:egal).
+      if (a === b) return a !== 0 || 1 / a === 1 / b;
+      var typeA = typeof a;
+      if( typeA != typeof b ) return false;
+      if( typeA == 'object' ) return a && b ? eq( a, b ) : a === b;
+      return a != a ? b != b : a === b;
   };
 
   // Is a given array, string, or object empty?