diff --git a/lodash.js b/lodash.js
index a33e8abdc..3c2d971fa 100644
--- a/lodash.js
+++ b/lodash.js
@@ -30,8 +30,9 @@
   /** Used as the TypeError message for "Functions" methods */
   var FUNC_ERROR_TEXT = 'Expected a function';
 
-  /** Used as a reference for the max length of an array */
-  var MAX_ARRAY_LENGTH = Math.pow(2, 32) - 1;
+  /** Used as references for the max length and index of an array */
+  var MAX_ARRAY_LENGTH = Math.pow(2, 32) - 1,
+      MAX_ARRAY_INDEX =  MAX_ARRAY_LENGTH - 1;
 
   /**
    * Used as the maximum length of an array-like value.
@@ -2285,13 +2286,14 @@
           valIsUndef = typeof value == 'undefined';
 
       while (low < high) {
-        var mid = (low + high) >>> 1,
-            computed = iteratee(array[mid]);
+        var mid = floor((low + high) / 2),
+            computed = iteratee(array[mid]),
+            isReflexive = computed === computed;
 
         if (valIsNaN) {
-          var setLow = computed === computed;
+          var setLow = isReflexive || retHighest;
         } else if (valIsUndef) {
-          setLow = computed === computed && typeof computed != 'undefined';
+          setLow = isReflexive && (retHighest || typeof computed != 'undefined');
         } else {
           setLow = retHighest ? (computed <= value) : (computed < value);
         }
@@ -2301,7 +2303,7 @@
           high = mid;
         }
       }
-      return high;
+      return nativeMin(high, MAX_ARRAY_INDEX);
     }
 
     /**
diff --git a/test/test.js b/test/test.js
index fb365b158..fa1bf1ff3 100644
--- a/test/test.js
+++ b/test/test.js
@@ -10056,24 +10056,24 @@
       ], function(array) {
         deepEqual(_.sortBy(array), expected);
         strictEqual(func(expected, 3), 2);
-        strictEqual(func(expected, undefined), 3);
-        strictEqual(func(expected, NaN), isSortedIndex ? 4 : 5);
+        strictEqual(func(expected, undefined), isSortedIndex ? 3 : 4);
+        strictEqual(func(expected, NaN), isSortedIndex ? 4 : 6);
       });
     });
 
-    test('`_.' + methodName + '` should support arrays larger than `Math.pow(2, 31) - 1`', 1, function() {
-      var length = Math.pow(2, 32) - 1,
-          index = length - 1,
-          array = Array(length),
+    test('`_.' + methodName + '` should support arrays larger than `Math.pow(2, 31) - 1`', 2, function() {
+      var array = [0],
+          length = Math.pow(2, 32) - 1,
           steps = 0;
 
+      array.length = length;
       if (array.length == length) {
-        array[index] = index;
-        func(array, index, function() { steps++; });
+        var actual = func(array, undefined, function() { steps++; });
         strictEqual(steps, 33);
+        strictEqual(actual, isSortedIndex ? 0 : (length - 1));
       }
       else {
-        skipTest();
+        skipTest(2);
       }
     });
   });