diff --git a/src/Assert.php b/src/Assert.php
index d32366d9..b4027793 100644
--- a/src/Assert.php
+++ b/src/Assert.php
@@ -699,7 +699,6 @@ public static function false($value, $message = '')
      */
     public static function ip($value, $message = '')
     {
-        static::string($value, $message);
         if (false === \filter_var($value, \FILTER_VALIDATE_IP)) {
             static::reportInvalidArgument(\sprintf(
                 $message ?: 'Expected a value to be an IP. Got: %s',
@@ -716,7 +715,6 @@ public static function ip($value, $message = '')
      */
     public static function ipv4($value, $message = '')
     {
-        static::string($value, $message);
         if (false === \filter_var($value, \FILTER_VALIDATE_IP, \FILTER_FLAG_IPV4)) {
             static::reportInvalidArgument(\sprintf(
                 $message ?: 'Expected a value to be an IPv4. Got: %s',
@@ -733,7 +731,6 @@ public static function ipv4($value, $message = '')
      */
     public static function ipv6($value, $message = '')
     {
-        static::string($value, $message);
         if (false === \filter_var($value, \FILTER_VALIDATE_IP, \FILTER_FLAG_IPV6)) {
             static::reportInvalidArgument(\sprintf(
                 $message ?: 'Expected a value to be an IPv6. Got %s',
@@ -750,7 +747,6 @@ public static function ipv6($value, $message = '')
      */
     public static function email($value, $message = '')
     {
-        static::string($value, $message);
         if (false === \filter_var($value, FILTER_VALIDATE_EMAIL)) {
             static::reportInvalidArgument(\sprintf(
                 $message ?: 'Expected a value to be a valid e-mail address. Got %s',
diff --git a/tests/AssertTest.php b/tests/AssertTest.php
index 4b22723b..a5b714c1 100644
--- a/tests/AssertTest.php
+++ b/tests/AssertTest.php
@@ -459,7 +459,7 @@ public function getTests()
             array('throws', array(function() { trigger_error('test'); }, 'Unthrowable'), false, false, 70000),
             array('throws', array(function() { throw new Error(); }, 'Throwable'), true, true, 70000),
             array('ip', array('192.168.0.1'), true),
-            array('ip', array(new ToStringClass('192.168.0.1')), false),
+            array('ip', array(new ToStringClass('192.168.0.1')), true),
             array('ip', array('255.255.255.255'), true),
             array('ip', array('0.0.0.0'), true),
             array('ip', array('2001:0db8:0000:0042:0000:8a2e:0370:7334'), true),
@@ -472,7 +472,7 @@ public function getTests()
             array('ip', array(null), false),
             array('ip', array(false), false),
             array('ipv4', array('192.168.0.1'), true),
-            array('ipv4', array(new ToStringClass('192.168.0.1')), false),
+            array('ipv4', array(new ToStringClass('192.168.0.1')), true),
             array('ipv4', array('255.255.255.255'), true),
             array('ipv4', array('0.0.0.0'), true),
             array('ipv4', array('2001:0db8:0000:0042:0000:8a2e:0370:7334'), false),
@@ -488,7 +488,7 @@ public function getTests()
             array('ipv6', array('255.255.255.255'), false),
             array('ipv6', array('0.0.0.0'), false),
             array('ipv6', array('2001:0db8:0000:0042:0000:8a2e:0370:7334'), true),
-            array('ipv6', array(new ToStringClass('2001:0db8:0000:0042:0000:8a2e:0370:7334')), false),
+            array('ipv6', array(new ToStringClass('2001:0db8:0000:0042:0000:8a2e:0370:7334')), true),
             array('ipv6', array('::ffff:192.0.2.1'), true),
             array('ipv6', array('::1'), true),
             array('ipv6', array('::'), true),
@@ -501,7 +501,7 @@ public function getTests()
             array('email', array(123), false),
             array('email', array('foo.com'), false),
             array('email', array('foo@bar.com'), true),
-            array('email', array(new ToStringClass('foo@bar.com')), false),
+            array('email', array(new ToStringClass('foo@bar.com')), true),
             array('uniqueValues', array(array('qwerty', 'qwerty')), false),
             array('uniqueValues', array(array('asdfg', 'qwerty')), true),
             array('uniqueValues', array(array(123, '123')), false),