diff --git a/cake/libs/set.php b/cake/libs/set.php
index 8d204b18c9c..b16aeb59a17 100644
--- a/cake/libs/set.php
+++ b/cake/libs/set.php
@@ -61,10 +61,10 @@ public static function merge($arr1, $arr2 = null) {
  * @param boolean $isArray Force to tell $var is an array when $var is empty
  * @return mixed Either filtered array, or true/false when in callback
  */
-	public static function filter($var, $isArray = false) {
-		foreach ((array)$var as $k => $v) {
-			if (!empty($v) && is_array($v)) {
-				$var[$k] = array_filter($v, array('Set', '_filter'));
+	public static function filter(array $var) {
+		foreach ($var as $k => $v) {
+			if (is_array($v)) {
+				$var[$k] = Set::filter($v);
 			}
 		}
 		return array_filter($var, array('Set', '_filter'));
diff --git a/cake/tests/cases/libs/set.test.php b/cake/tests/cases/libs/set.test.php
index bbd3e581cd6..b974bfe3d6d 100644
--- a/cake/tests/cases/libs/set.test.php
+++ b/cake/tests/cases/libs/set.test.php
@@ -100,8 +100,15 @@ function testFilter() {
 		$result = Set::filter(array(1, array('empty', false)));
 		$expected = array(1, array('empty'));
 		$this->assertEqual($expected, $result);
+
+		$result = Set::filter(array(1, array('2', false, array(3, null))));
+		$expected = array(1, array('2', 2 => array(3)));
+		$this->assertEqual($expected, $result);
+
+		$this->assertSame(array(), Set::filter(array()));
 	}
 
+
 /**
  * testNumericArrayCheck method
  *