diff --git a/src/CacheFile.php b/src/CacheFile.php
index 60ee9d0..4d77e90 100644
--- a/src/CacheFile.php
+++ b/src/CacheFile.php
@@ -266,7 +266,7 @@ public function getAll()
      */
     public function lock($key, $iteration = 15)
     {
-        throw new CacheException(CacheException::UNKNOWN_METHOD, ['method' => __METHOD__]);
+        return true;
     }
 
     /**
@@ -274,7 +274,7 @@ public function lock($key, $iteration = 15)
      */
     public function unlock($key)
     {
-        throw new CacheException(CacheException::UNKNOWN_METHOD, ['method' => __METHOD__]);
+        return true;
     }
 
     /**
diff --git a/tests/CacheFileTest.php b/tests/CacheFileTest.php
index c09d77c..aa43313 100644
--- a/tests/CacheFileTest.php
+++ b/tests/CacheFileTest.php
@@ -101,11 +101,11 @@ public function testGetAllKeys(CacheInterface $cache)
 
     /**
      * @dataProvider providerCache
-     * @expectedException \rock\cache\CacheException
      */
     public function testLockAndUnlock(CacheInterface $cache)
     {
-        $cache->lock('key1');
+        $this->assertTrue($cache->lock('key1'));
+        $this->assertTrue($cache->unlock('key1'));
     }
 
     /**