diff --git a/tests/src/Generator/OpenSslGeneratorTest.php b/tests/src/Generator/OpenSslGeneratorTest.php
new file mode 100644
index 0000000..4ab3e1c
--- /dev/null
+++ b/tests/src/Generator/OpenSslGeneratorTest.php
@@ -0,0 +1,59 @@
+<?php
+
+namespace Ramsey\Uuid\Test\Generator;
+
+use Ramsey\Uuid\Generator\OpenSslGenerator;
+use Ramsey\Uuid\Test\TestCase;
+use AspectMock\Test as AspectMock;
+
+class OpenSslGeneratorTest extends TestCase
+{
+    public function setUp()
+    {
+        $this->skipIfHhvm();
+        parent::setUp();
+    }
+
+    public function tearDown()
+    {
+        parent::tearDown();
+        AspectMock::clean();
+    }
+
+    public function lengthAndHexDataProvider()
+    {
+        return [
+            [6, '005340670735'],
+            [10, '292be7f7e462b2b2d24a'],
+            [12, 'a9e3504ed48cffefe412eb70']
+        ];
+    }
+
+    /**
+     * @dataProvider lengthAndHexDataProvider
+     * @runInSeparateProcess
+     * @preserveGlobalState disabled
+     */
+    public function testGenerateUsesOpenSsl($length, $hex)
+    {
+        $bytes = hex2bin($hex);
+        $openSsl = AspectMock::func('Ramsey\Uuid\Generator', 'openssl_random_pseudo_bytes', $bytes);
+        $generator = new OpenSslGenerator();
+        $generator->generate($length);
+
+        $openSsl->verifyInvokedOnce([$length]);
+    }
+
+    /**
+     * @dataProvider lengthAndHexDataProvider
+     * @runInSeparateProcess
+     * @preserveGlobalState disabled
+     */
+    public function testGenerateReturnsRandomBytes($length, $hex)
+    {
+        $bytes = hex2bin($hex);
+        AspectMock::func('Ramsey\Uuid\Generator', 'openssl_random_pseudo_bytes', $bytes);
+        $generator = new OpenSslGenerator();
+        $this->assertEquals($bytes, $generator->generate($length));
+    }
+}