diff --git a/src/Lock.php b/src/Lock.php
index 2c7099b..3b79ba8 100644
--- a/src/Lock.php
+++ b/src/Lock.php
@@ -15,6 +15,7 @@ class Lock
     static private $data = [];
     static private $dir = null;
     static private $keyPrefix = null;
+    static private $defaultLockTimeout = 1.5;
 
     /**
      * 
@@ -52,6 +53,24 @@ static function setKeyPrefix($prefix)
         self::$keyPrefix = $prefix;
     }
 
+    /**
+     * 
+     * @return string
+     */
+    static function getDefaultLockTimeout()
+    {
+        return self::$defaultLockTimeout;
+    }
+
+    /**
+     * 
+     * @param string $prefix
+     */
+    static function setDefaultLockTimeout($seconds)
+    {
+        self::$defaultLockTimeout = $seconds;
+    }
+
     /**
      * 
      * @param mixed $key
@@ -61,7 +80,7 @@ static function setKeyPrefix($prefix)
     static public function acquire($key, $options = [])
     {
         $keyMD5 = md5(self::$keyPrefix . serialize($key));
-        $timeout = isset($options['timeout']) ? (float) $options['timeout'] : 1.5;
+        $timeout = isset($options['timeout']) ? (float) $options['timeout'] : self::$defaultLockTimeout;
         $retryInterval = 0.5;
         $maxRetriesCount = floor($timeout / $retryInterval);
         $lock = function() use ($keyMD5) {
@@ -118,7 +137,11 @@ static public function acquire($key, $options = [])
     static public function exists($key)
     {
         $keyMD5 = md5(self::$keyPrefix . serialize($key));
-        $filename = self::getLocksDir() . $keyMD5 . '.lock';
+        $dir = self::getLocksDir();
+        if (!is_dir($dir)) {
+            return false;
+        }
+        $filename = $dir . $keyMD5 . '.lock';
         set_error_handler(function($errno, $errstr) {
             throw new \Exception($errstr);
         });
@@ -151,6 +174,9 @@ static public function release($key)
         $keyMD5 = md5(self::$keyPrefix . serialize($key));
         if (!isset(self::$data[$keyMD5])) {
             throw new \Exception('A lock name "' . $key . '" does not exists in current process!');
+        }
+        $dir = self::getLocksDir();
+        if (!is_dir($dir)) {
             return;
         }
         set_error_handler(function($errno, $errstr) {
@@ -159,7 +185,7 @@ static public function release($key)
         try {
             if (flock(self::$data[$keyMD5], LOCK_UN) && fclose(self::$data[$keyMD5])) {
                 try {
-                    $filename = self::getLocksDir() . $keyMD5 . '.lock';
+                    $filename = $dir . $keyMD5 . '.lock';
                     $tempFilename = $filename . '.' . md5(uniqid() . rand(0, 999999));
                     $renameResult = rename($filename, $tempFilename);
                     if ($renameResult) {
diff --git a/tests/LocksTest.php b/tests/LocksTest.php
index 2c33147..718496f 100644
--- a/tests/LocksTest.php
+++ b/tests/LocksTest.php
@@ -48,6 +48,7 @@ public function testRelease()
     public function testKeyPrefix()
     {
         Lock::setKeyPrefix('prefix1');
+        $this->assertTrue(Lock::getKeyPrefix() === 'prefix1');
         $this->assertTrue(Lock::exists('test1') === false);
         Lock::acquire('test1');
         $this->assertTrue(Lock::exists('test1') === true);
@@ -67,6 +68,26 @@ public function testExists()
         $this->assertTrue(Lock::exists('test3') === false);
     }
 
+    /**
+     * 
+     */
+    public function testTimeout()
+    {
+        Lock::setDefaultLockTimeout(2.5);
+        $this->assertTrue(Lock::getDefaultLockTimeout() === 2.5);
+        Lock::acquire('test2');
+        try {
+            $time = microtime(true);
+            Lock::acquire('test2');
+            throw new Exception('Should not get here');
+        } catch (Exception $e) {
+            $time = microtime(true) - $time;
+            $this->assertTrue($e->getMessage() === 'Cannot acquire lock for "test2"');
+            $this->assertTrue($time > 2.5);
+            $this->assertTrue($time < 3);
+        }
+    }
+
     /**
      * 
      */