diff --git a/src/Validator/Boolean.php b/src/Validator/Boolean.php
index bc91cc0a..30779941 100644
--- a/src/Validator/Boolean.php
+++ b/src/Validator/Boolean.php
@@ -24,6 +24,19 @@
  */
 class Boolean extends Validator
 {
+    /**
+     * @var bool
+     */
+    protected $strings = false;
+
+    /**
+     * @param array $strings
+     */
+    public function __construct(bool $strings = false)
+    {
+        $this->strings = $strings;
+    }
+
     /**
      * Get Description
      *
@@ -46,10 +59,14 @@ public function getDescription()
      */
     public function isValid($value)
     {
-        if (!\is_bool($value)) {
-            return false;
+        if($this->strings && ($value === 'true' || $value === 'false')) {
+            return true;
+        }
+
+        if (\is_bool($value)) {
+            return true;
         }
 
-        return true;
+        return false;
     }
 }
\ No newline at end of file
diff --git a/tests/Validator/BooleanTest.php b/tests/Validator/BooleanTest.php
index c0a682b6..3e9073e2 100755
--- a/tests/Validator/BooleanTest.php
+++ b/tests/Validator/BooleanTest.php
@@ -24,7 +24,6 @@ class BooleanTest extends TestCase
 
     public function setUp()
     {
-        $this->boolean = new Boolean();
     }
 
     public function tearDown()
@@ -34,9 +33,23 @@ public function tearDown()
 
     public function testIsValid()
     {
-        // Assertions
+        $this->boolean = new Boolean();
+        
+        $this->assertEquals(true, $this->boolean->isValid(true));
+        $this->assertEquals(true, $this->boolean->isValid(false));
+        $this->assertEquals(false, $this->boolean->isValid('false'));
+        $this->assertEquals(false, $this->boolean->isValid('true'));
+        $this->assertEquals(false, $this->boolean->isValid(['string', 'string']));
+        $this->assertEquals(false, $this->boolean->isValid('string'));
+        $this->assertEquals(false, $this->boolean->isValid(1));
+        $this->assertEquals(false, $this->boolean->isValid(1.2));
+
+        $this->boolean = new Boolean(true);
+
         $this->assertEquals(true, $this->boolean->isValid(true));
         $this->assertEquals(true, $this->boolean->isValid(false));
+        $this->assertEquals(true, $this->boolean->isValid('false'));
+        $this->assertEquals(true, $this->boolean->isValid('true'));
         $this->assertEquals(false, $this->boolean->isValid(['string', 'string']));
         $this->assertEquals(false, $this->boolean->isValid('string'));
         $this->assertEquals(false, $this->boolean->isValid(1));