diff --git a/lodash.src.js b/lodash.src.js
index 25475f601..b45bcfc67 100644
--- a/lodash.src.js
+++ b/lodash.src.js
@@ -137,18 +137,6 @@
     return RegExp(upper + '+(?=' + upper + lower + ')|' + upper + '?' + lower + '|' + upper + '+|[0-9]+', 'g');
   }());
 
-  /** Used to detect and test for whitespace. */
-  var whitespace = (
-    // Basic whitespace characters.
-    ' \t\x0b\f\xa0\ufeff' +
-
-    // Line terminators.
-    '\n\r\u2028\u2029' +
-
-    // Unicode category "Zs" space separators.
-    '\u1680\u180e\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u202f\u205f\u3000'
-  );
-
   /** Used to assign default `context` object properties. */
   var contextProps = [
     'Array', 'ArrayBuffer', 'Date', 'Error', 'Float32Array', 'Float64Array',
@@ -10517,25 +10505,16 @@
      * // => [6, 8, 10]
      */
     function parseInt(string, radix, guard) {
-      if (guard && isIterateeCall(string, radix, guard)) {
+      // Firefox < 21 and Opera < 15 follow ES3 for `parseInt`.
+      // Chrome fails to trim leading <BOM> whitespace characters.
+      // See https://code.google.com/p/v8/issues/detail?id=3109 for more details.
+      if (guard ? isIterateeCall(string, radix, guard) : radix == null) {
         radix = 0;
+      } else if (radix) {
+        radix = +radix;
       }
-      return nativeParseInt(string, radix);
-    }
-    // Fallback for environments with pre-ES5 implementations.
-    if (nativeParseInt(whitespace + '08') != 8) {
-      parseInt = function(string, radix, guard) {
-        // Firefox < 21 and Opera < 15 follow ES3 for `parseInt`.
-        // Chrome fails to trim leading <BOM> whitespace characters.
-        // See https://code.google.com/p/v8/issues/detail?id=3109 for more details.
-        if (guard ? isIterateeCall(string, radix, guard) : radix == null) {
-          radix = 0;
-        } else if (radix) {
-          radix = +radix;
-        }
-        string = trim(string);
-        return nativeParseInt(string, radix || (reHasHexPrefix.test(string) ? 16 : 10));
-      };
+      string = trim(string);
+      return nativeParseInt(string, radix || (reHasHexPrefix.test(string) ? 16 : 10));
     }
 
     /**