diff --git a/FtpClient.php b/FtpClient.php
index 30baaad..b550e0d 100644
--- a/FtpClient.php
+++ b/FtpClient.php
@@ -12,6 +12,10 @@
 
 namespace yii2mod\ftp;
 
+use Countable;
+use Exception;
+use RuntimeException;
+
 /**
  * The FTP and SSL-FTP client for PHP.
  *
@@ -19,7 +23,6 @@
  * @method bool cdup() cdup() Changes to the parent directory
  * @method bool chdir() chdir(string $directory) Changes the current directory on a FTP server
  * @method int chmod() chmod(int $mode, string $filename) Set permissions on a file via FTP
- * @method bool close() close() Closes an FTP connection
  * @method bool delete() delete(string $path) Deletes a file on the FTP server
  * @method bool exec() exec(string $command) Requests execution of a command on the FTP server
  * @method bool fget() fget(resource $handle, string $remote_file, int $mode, int $resumepos = 0) Downloads a file from the FTP server and saves to an open file
@@ -45,7 +48,7 @@
  *
  * @see  `nicolab/php-ftp-client`
  */
-class FtpClient implements \Countable
+class FtpClient implements Countable
 {
     /**
      * The connection with the server
@@ -87,8 +90,24 @@ public function __construct($connection = null)
     public function __destruct()
     {
         if ($this->conn) {
-            $this->ftp->close();
+            $this->close();
+            $this->conn = null;
+        }
+    }
+
+    /**
+     * @return bool
+     */
+    public function close()
+    {
+        if (!$this->ftp) {
+            $this->conn = null;
+            return true;
         }
+        $return = $this->ftp->close();
+        $this->conn = null;
+        $this->ftp = null;
+        return $return;
     }
 
     /**
@@ -100,9 +119,10 @@ public function __destruct()
      * @param $method
      * @param array $arguments
      *
+     * @return mixed
+     * @throws FtpException
      * @internal param string $function
      *
-     * @return mixed
      */
     public function __call($method, array $arguments)
     {
@@ -173,6 +193,7 @@ public function connect($host, $ssl = false, $port = 21, $timeout = 90)
      * @param bool $include_hidden
      *
      * @return FtpClient
+     * @throws FtpException
      */
     public function getAll($source_directory, $target_directory, $mode = FTP_BINARY, $include_hidden = false)
     {
@@ -182,9 +203,11 @@ public function getAll($source_directory, $target_directory, $mode = FTP_BINARY,
         foreach ($d as $file) {
             $new_source_directory = $source_directory . '/' . $file['name'];
             $new_target_directory = $target_directory . '/' . $file['name'];
-            if ($file['type'] == 'directory') {
+            if ($file['type'] === 'directory') {
                 if (!is_dir($new_target_directory)) {
-                    mkdir($new_target_directory);
+                    if (!mkdir($new_target_directory) && !is_dir($new_target_directory)) {
+                        throw new RuntimeException(sprintf('Directory "%s" was not created', $new_target_directory));
+                    }
                 }
                 $this->getAll($new_source_directory, $new_target_directory, $mode, $include_hidden);
             } else {
@@ -350,15 +373,16 @@ public function nlist($directory = '.', $recursive = false, $filter = 'sort')
     /**
      * Creates a directory
      *
+     * @param string $directory The directory
+     * @param bool $recursive
+     *
+     * @return string|false
+     * @throws FtpException
      * @see FtpClient::rmdir()
      * @see FtpClient::remove()
      * @see FtpClient::put()
      * @see FtpClient::putAll()
      *
-     * @param string $directory The directory
-     * @param bool $recursive
-     *
-     * @return string|false
      */
     public function mkdir($directory, $recursive = false)
     {
@@ -413,13 +437,14 @@ public function rmdir($directory, $recursive = true)
     /**
      * Empty directory
      *
+     * @param string $directory
+     *
+     * @return bool
+     * @throws FtpException
      * @see FtpClient::remove()
      * @see FtpClient::delete()
      * @see FtpClient::rmdir()
      *
-     * @param string $directory
-     *
-     * @return bool
      */
     public function cleanDir($directory)
     {
@@ -449,12 +474,9 @@ public function cleanDir($directory)
     public function remove($path, $recursive = false)
     {
         try {
-            if (@$this->ftp->delete($path) || ($this->isDir($path) and @$this->rmdir($path, $recursive))) {
-                return true;
-            }
-
-            return false;
-        } catch (\Exception $e) {
+            return @$this->ftp->delete($path)
+                || ($this->isDir($path) and @$this->rmdir($path, $recursive));
+        } catch (Exception $e) {
             return false;
         }
     }
@@ -490,25 +512,27 @@ public function isDir($directory)
      * @param string $directory
      *
      * @return bool
+     * @throws FtpException
      */
     public function isEmpty($directory)
     {
-        return $this->count($directory, null, false) === 0 ? true : false;
+        return $this->count($directory, null, false) === 0;
     }
 
     /**
      * Scan a directory and returns the details of each item.
      *
-     * @see FtpClient::nlist()
-     * @see FtpClient::rawlist()
-     * @see FtpClient::parseRawList()
-     * @see FtpClient::dirSize()
-     *
      * @param string $directory
      * @param bool $recursive
      * @param bool $includeHidden
      *
      * @return array
+     * @throws FtpException
+     * @see FtpClient::rawlist()
+     * @see FtpClient::parseRawList()
+     * @see FtpClient::dirSize()
+     *
+     * @see FtpClient::nlist()
      */
     public function scanDir($directory = '.', $recursive = false, $includeHidden = false)
     {
@@ -523,6 +547,7 @@ public function scanDir($directory = '.', $recursive = false, $includeHidden = f
      * @param bool $include_hidden false by default
      *
      * @return int The size in bytes
+     * @throws FtpException
      */
     public function dirSize($directory = '.', $recursive = true, $include_hidden = false)
     {
@@ -544,6 +569,7 @@ public function dirSize($directory = '.', $recursive = true, $include_hidden = f
      * @param bool $include_hidden
      *
      * @return int
+     * @throws FtpException
      */
     public function count($directory = '.', $type = null, $recursive = true, $include_hidden = false)
     {
@@ -677,7 +703,7 @@ public function rawlist($directory = '.', $recursive = false, $includeHidden = f
         $items = [];
         if (false == $recursive) {
             foreach ($list as $path => $item) {
-                $chunks = preg_split("/\s+/", $item);
+                $chunks = preg_split('/\s+/', $item);
                 // if not "name"
                 if (empty($chunks[8]) || $chunks[8] == '.' || $chunks[8] == '..') {
                     continue;
@@ -702,7 +728,7 @@ public function rawlist($directory = '.', $recursive = false, $includeHidden = f
             ) {
                 continue;
             }
-            $chunks = preg_split("/\s+/", $item);
+            $chunks = preg_split('/\s+/', $item);
             // if not "name"
             if (empty($chunks[8]) || $chunks[8] == '.' || $chunks[8] == '..') {
                 continue;
@@ -739,7 +765,7 @@ public function parseRawList(array $rawlist)
         $items = [];
         $path = '';
         foreach ($rawlist as $key => $child) {
-            $chunks = preg_split("/\s+/", $child);
+            $chunks = preg_split('/\s+/', $child);
             if (isset($chunks[8]) && ($chunks[8] == '.' or $chunks[8] == '..')) {
                 continue;
             }
diff --git a/FtpException.php b/FtpException.php
index 5316bff..94ccee9 100644
--- a/FtpException.php
+++ b/FtpException.php
@@ -12,9 +12,11 @@
 
 namespace yii2mod\ftp;
 
+use Exception;
+
 /**
  * The FtpException class. Exception thrown if an error on runtime of the FTP client occurs.
  */
-class FtpException extends \Exception
+class FtpException extends Exception
 {
 }
diff --git a/FtpWrapper.php b/FtpWrapper.php
index efdb03d..7eb11b7 100644
--- a/FtpWrapper.php
+++ b/FtpWrapper.php
@@ -89,7 +89,7 @@ public function __call($function, array $arguments)
             return call_user_func_array($function, $arguments);
         }
 
-        throw new FtpException("{$function} is not a valid FTP function");
+        throw new FtpException("$function is not a valid FTP function");
     }
 
     /**