diff --git a/src/Ratchet/Component/Server/IpBlackListComponent.php b/src/Ratchet/Component/Server/IpBlackListComponent.php
index 1989480..5e2d06c 100644
--- a/src/Ratchet/Component/Server/IpBlackListComponent.php
+++ b/src/Ratchet/Component/Server/IpBlackListComponent.php
@@ -34,7 +34,9 @@ class IpBlackListComponent implements MessageComponentInterface {
      * @return IpBlackList
      */
     public function unblockAddress($ip) {
-        unset($this->_blacklist[$this->filterAddress($ip)]);
+        if (isset($this->_blacklist[$this->filterAddress($ip)])) {
+            unset($this->_blacklist[$this->filterAddress($ip)]);
+        }
 
         return $this;
     }
diff --git a/tests/Ratchet/Tests/Component/Server/IpBlackListComponentTest.php b/tests/Ratchet/Tests/Component/Server/IpBlackListComponentTest.php
index 874bc5b..c164803 100644
--- a/tests/Ratchet/Tests/Component/Server/IpBlackListComponentTest.php
+++ b/tests/Ratchet/Tests/Component/Server/IpBlackListComponentTest.php
@@ -84,4 +84,8 @@ class IpBlackListComponentTest extends \PHPUnit_Framework_TestCase {
     public function testFilterAddress($expected, $input) {
         $this->assertEquals($expected, $this->_comp->filterAddress($input));
     }
+
+    public function testUnblockingSilentlyFails() {
+        $this->assertInstanceOf('\\Ratchet\\Component\\Server\\IpBlackListComponent', $this->_comp->unblockAddress('localhost'));
+    }
 }
\ No newline at end of file