diff --git a/src/Symmetric/Openssl.php b/src/Symmetric/Openssl.php
index 21de981..6982fc2 100644
--- a/src/Symmetric/Openssl.php
+++ b/src/Symmetric/Openssl.php
@@ -90,6 +90,7 @@ class Openssl implements SymmetricInterface
         'cfb',
         'ofb',
         'ecb',
+        'ctr',
     ];
 
     /**
diff --git a/test/Symmetric/OpensslTest.php b/test/Symmetric/OpensslTest.php
index ab4eff5..fde8431 100644
--- a/test/Symmetric/OpensslTest.php
+++ b/test/Symmetric/OpensslTest.php
@@ -23,4 +23,14 @@ class OpensslTest extends AbstractTest
     protected $default_mode = 'cbc';
 
     protected $default_padding = 'pkcs7';
+
+    public function testCtrMode()
+    {
+        if (!in_array('aes-256-ctr', openssl_get_cipher_methods())) {
+            $this->markTestSkipped('The CTR mode is not supported');
+        }
+        $this->crypt->setAlgorithm('aes');
+        $this->crypt->setMode('ctr');
+        $this->assertEquals('ctr', $this->crypt->getMode());
+    }
 }