diff --git a/src/Backup/Target/Compression/Abstraction.php b/src/Backup/Target/Compression/Abstraction.php
index 804ab535..ff16f486 100644
--- a/src/Backup/Target/Compression/Abstraction.php
+++ b/src/Backup/Target/Compression/Abstraction.php
@@ -120,4 +120,12 @@ public function getMimeType() : string
     {
         return $this->mimeType;
     }
+
+    /**
+     * @return string
+     */
+    public function __toString(): string
+    {
+        return $this->cmd;
+    }
 }
diff --git a/src/Cli/Executable/Abstraction.php b/src/Cli/Executable/Abstraction.php
index 59b0713f..3ebd7116 100644
--- a/src/Cli/Executable/Abstraction.php
+++ b/src/Cli/Executable/Abstraction.php
@@ -1,6 +1,7 @@
 <?php
 namespace phpbu\App\Cli\Executable;
 
+use phpbu\App\Cli\Executable;
 use phpbu\App\Util\Cli;
 use SebastianFeldmann\Cli\CommandLine;
 
@@ -15,7 +16,7 @@
  * @link       http://phpbu.de/
  * @since      Class available since Release 2.1.0
  */
-abstract class Abstraction
+abstract class Abstraction implements Executable
 {
     /**
      * Command name.
@@ -106,4 +107,12 @@ public function getCommandPrintable() : string
     {
         return $this->getCommand();
     }
+
+    /**
+     * @return string
+     */
+    public function __toString() : string
+    {
+        return $this->getCommand();
+    }
 }
diff --git a/src/Cli/Executable/Arangodump.php b/src/Cli/Executable/Arangodump.php
index e77ee1c2..efc9a57f 100644
--- a/src/Cli/Executable/Arangodump.php
+++ b/src/Cli/Executable/Arangodump.php
@@ -1,7 +1,6 @@
 <?php
 namespace phpbu\App\Cli\Executable;
 
-use phpbu\App\Cli\Executable;
 use phpbu\App\Exception;
 use SebastianFeldmann\Cli\CommandLine;
 use SebastianFeldmann\Cli\Command\Executable as Cmd;
@@ -18,7 +17,7 @@
  * @link       http://phpbu.de/
  * @since      Class available since Release 2.0.0
  */
-class Arangodump extends Abstraction implements Executable
+class Arangodump extends Abstraction
 {
     use OptionMasker;
 
diff --git a/src/Cli/Executable/Compressor.php b/src/Cli/Executable/Compressor.php
index 110f7b35..97412e51 100644
--- a/src/Cli/Executable/Compressor.php
+++ b/src/Cli/Executable/Compressor.php
@@ -1,7 +1,6 @@
 <?php
 namespace phpbu\App\Cli\Executable;
 
-use phpbu\App\Cli\Executable;
 use phpbu\App\Exception;
 use SebastianFeldmann\Cli\CommandLine;
 use SebastianFeldmann\Cli\Command\Executable as Cmd;
@@ -17,7 +16,7 @@
  * @link       http://phpbu.de/
  * @since      Class available since Release 1.0.0
  */
-class Compressor extends Abstraction implements Executable
+class Compressor extends Abstraction
 {
     /**
      * File to compress.
diff --git a/src/Cli/Executable/Elasticdump.php b/src/Cli/Executable/Elasticdump.php
index 74171c94..f74ab45a 100644
--- a/src/Cli/Executable/Elasticdump.php
+++ b/src/Cli/Executable/Elasticdump.php
@@ -1,7 +1,6 @@
 <?php
 namespace phpbu\App\Cli\Executable;
 
-use phpbu\App\Cli\Executable;
 use phpbu\App\Exception;
 use phpbu\App\Util;
 use SebastianFeldmann\Cli\CommandLine;
@@ -19,7 +18,7 @@
  * @link       http://phpbu.de/
  * @since      Class available since Release 2.1.0
  */
-class Elasticdump extends Abstraction implements Executable
+class Elasticdump extends Abstraction
 {
     use OptionMasker;
 
diff --git a/src/Cli/Executable/Gpg.php b/src/Cli/Executable/Gpg.php
index 20e99742..fc0f946a 100644
--- a/src/Cli/Executable/Gpg.php
+++ b/src/Cli/Executable/Gpg.php
@@ -1,7 +1,6 @@
 <?php
 namespace phpbu\App\Cli\Executable;
 
-use phpbu\App\Cli\Executable;
 use phpbu\App\Exception;
 use SebastianFeldmann\Cli\CommandLine;
 use SebastianFeldmann\Cli\Command\Executable as Cmd;
@@ -17,7 +16,7 @@
  * @link       https://phpbu.de/
  * @since      Class available since Release 6.0.1
  */
-class Gpg extends Abstraction implements Executable
+class Gpg extends Abstraction
 {
     use OptionMasker;
 
diff --git a/src/Cli/Executable/Influxdump.php b/src/Cli/Executable/Influxdump.php
index c3cb61e3..ae38d029 100644
--- a/src/Cli/Executable/Influxdump.php
+++ b/src/Cli/Executable/Influxdump.php
@@ -2,7 +2,6 @@
 
 namespace phpbu\App\Cli\Executable;
 
-use phpbu\App\Cli\Executable;
 use SebastianFeldmann\Cli\CommandLine;
 use SebastianFeldmann\Cli\Command\Executable as Cmd;
 
@@ -18,7 +17,7 @@
  * @link       http://phpbu.de/
  * @since      Class available since Release 2.1.12
  */
-class Influxdump extends Abstraction implements Executable
+class Influxdump extends Abstraction
 {
     use OptionMasker;
 
diff --git a/src/Cli/Executable/Innobackupex.php b/src/Cli/Executable/Innobackupex.php
index 0fe86a8c..8ef4ccf2 100644
--- a/src/Cli/Executable/Innobackupex.php
+++ b/src/Cli/Executable/Innobackupex.php
@@ -1,7 +1,6 @@
 <?php
 namespace phpbu\App\Cli\Executable;
 
-use phpbu\App\Cli\Executable;
 use phpbu\App\Exception;
 use SebastianFeldmann\Cli\CommandLine;
 use SebastianFeldmann\Cli\Command\Executable as Cmd;
@@ -18,7 +17,7 @@
  * @link       http://phpbu.de/
  * @since      Class available since Release 2.1.0
  */
-class Innobackupex extends Abstraction implements Executable
+class Innobackupex extends Abstraction
 {
     use OptionMasker;
 
diff --git a/src/Cli/Executable/Ldapdump.php b/src/Cli/Executable/Ldapdump.php
index dfb70bce..2c08018f 100644
--- a/src/Cli/Executable/Ldapdump.php
+++ b/src/Cli/Executable/Ldapdump.php
@@ -3,7 +3,6 @@
 namespace phpbu\App\Cli\Executable;
 
 use phpbu\App\Backup\Target\Compression;
-use phpbu\App\Cli\Executable;
 use phpbu\App\Util\Cli;
 use SebastianFeldmann\Cli\CommandLine;
 use SebastianFeldmann\Cli\Command\Executable as Cmd;
@@ -20,7 +19,7 @@
  * @link       http://phpbu.de/
  * @since      Class available since Release 2.1.12
  */
-class Ldapdump extends Abstraction implements Executable
+class Ldapdump extends Abstraction
 {
     use OptionMasker;
 
diff --git a/src/Cli/Executable/Mcrypt.php b/src/Cli/Executable/Mcrypt.php
index 72f9bc2d..25aee10a 100644
--- a/src/Cli/Executable/Mcrypt.php
+++ b/src/Cli/Executable/Mcrypt.php
@@ -1,7 +1,6 @@
 <?php
 namespace phpbu\App\Cli\Executable;
 
-use phpbu\App\Cli\Executable;
 use phpbu\App\Exception;
 use SebastianFeldmann\Cli\CommandLine;
 use SebastianFeldmann\Cli\Command\Executable as Cmd;
@@ -17,7 +16,7 @@
  * @link       http://phpbu.de/
  * @since      Class available since Release 2.1.0
  */
-class Mcrypt extends Abstraction implements Executable
+class Mcrypt extends Abstraction
 {
     use OptionMasker;
 
diff --git a/src/Cli/Executable/Mongodump.php b/src/Cli/Executable/Mongodump.php
index b4d22ff5..36175940 100644
--- a/src/Cli/Executable/Mongodump.php
+++ b/src/Cli/Executable/Mongodump.php
@@ -1,7 +1,6 @@
 <?php
 namespace phpbu\App\Cli\Executable;
 
-use phpbu\App\Cli\Executable;
 use phpbu\App\Exception;
 use SebastianFeldmann\Cli\CommandLine;
 use SebastianFeldmann\Cli\Command\Executable as Cmd;
@@ -17,7 +16,7 @@
  * @link       http://phpbu.de/
  * @since      Class available since Release 2.1.0
  */
-class Mongodump extends Abstraction implements Executable
+class Mongodump extends Abstraction
 {
     use OptionMasker;
 
diff --git a/src/Cli/Executable/Mysql.php b/src/Cli/Executable/Mysql.php
index f77090ce..3524709c 100644
--- a/src/Cli/Executable/Mysql.php
+++ b/src/Cli/Executable/Mysql.php
@@ -1,7 +1,6 @@
 <?php
 namespace phpbu\App\Cli\Executable;
 
-use phpbu\App\Cli\Executable;
 use SebastianFeldmann\Cli\CommandLine;
 use SebastianFeldmann\Cli\Command\Executable as Cmd;
 
@@ -16,7 +15,7 @@
  * @link       http://phpbu.de/
  * @since      Class available since Release 6.0-dev
  */
-class Mysql extends Abstraction implements Executable
+class Mysql extends Abstraction
 {
     use OptionMasker;
 
diff --git a/src/Cli/Executable/Mysqldump.php b/src/Cli/Executable/Mysqldump.php
index 1e04500c..6784196e 100644
--- a/src/Cli/Executable/Mysqldump.php
+++ b/src/Cli/Executable/Mysqldump.php
@@ -2,10 +2,8 @@
 namespace phpbu\App\Cli\Executable;
 
 use phpbu\App\Backup\Target\Compression;
-use phpbu\App\Cli\Executable;
 use phpbu\App\Exception;
 use phpbu\App\Util\Cli;
-use phpbu\App\Util\Str;
 use SebastianFeldmann\Cli\CommandLine;
 use SebastianFeldmann\Cli\Command\Executable as Cmd;
 
@@ -20,7 +18,7 @@
  * @link       http://phpbu.de/
  * @since      Class available since Release 1.0.0
  */
-class Mysqldump extends Abstraction implements Executable
+class Mysqldump extends Abstraction
 {
     use OptionMasker;
 
diff --git a/src/Cli/Executable/Mysqlimport.php b/src/Cli/Executable/Mysqlimport.php
index d59ba292..657047a1 100644
--- a/src/Cli/Executable/Mysqlimport.php
+++ b/src/Cli/Executable/Mysqlimport.php
@@ -1,7 +1,6 @@
 <?php
 namespace phpbu\App\Cli\Executable;
 
-use phpbu\App\Cli\Executable;
 use phpbu\App\Exception;
 use SebastianFeldmann\Cli\Command\Executable as Cmd;
 use SebastianFeldmann\Cli\CommandLine;
@@ -17,7 +16,7 @@
  * @link       http://phpbu.de/
  * @since      Class available since Release 6.0-dev
  */
-class Mysqlimport extends Abstraction implements Executable
+class Mysqlimport extends Abstraction
 {
     use OptionMasker;
 
diff --git a/src/Cli/Executable/OpenSSL.php b/src/Cli/Executable/OpenSSL.php
index d51bd799..68c4be15 100644
--- a/src/Cli/Executable/OpenSSL.php
+++ b/src/Cli/Executable/OpenSSL.php
@@ -1,7 +1,6 @@
 <?php
 namespace phpbu\App\Cli\Executable;
 
-use phpbu\App\Cli\Executable;
 use phpbu\App\Exception;
 use SebastianFeldmann\Cli\CommandLine;
 use SebastianFeldmann\Cli\Command\Executable as Cmd;
@@ -17,7 +16,7 @@
  * @link       http://phpbu.de/
  * @since      Class available since Release 2.1.6
  */
-class OpenSSL extends Abstraction implements Executable
+class OpenSSL extends Abstraction
 {
     use OptionMasker;
 
diff --git a/src/Cli/Executable/Pgdump.php b/src/Cli/Executable/Pgdump.php
index b9526501..78fe6bd8 100644
--- a/src/Cli/Executable/Pgdump.php
+++ b/src/Cli/Executable/Pgdump.php
@@ -1,7 +1,6 @@
 <?php
 namespace phpbu\App\Cli\Executable;
 
-use phpbu\App\Cli\Executable;
 use phpbu\App\Exception;
 use SebastianFeldmann\Cli\CommandLine;
 use SebastianFeldmann\Cli\Command\Executable as Cmd;
@@ -17,7 +16,7 @@
  * @link       http://phpbu.de/
  * @since      Class available since Release 1.0.0
  */
-class Pgdump extends Abstraction implements Executable
+class Pgdump extends Abstraction
 {
     use OptionMasker;
 
diff --git a/src/Cli/Executable/RedisCli.php b/src/Cli/Executable/RedisCli.php
index f92b8328..1248f264 100644
--- a/src/Cli/Executable/RedisCli.php
+++ b/src/Cli/Executable/RedisCli.php
@@ -1,7 +1,6 @@
 <?php
 namespace phpbu\App\Cli\Executable;
 
-use phpbu\App\Cli\Executable;
 use phpbu\App\Exception;
 use SebastianFeldmann\Cli\CommandLine;
 use SebastianFeldmann\Cli\Command\Executable as Cmd;
@@ -17,7 +16,7 @@
  * @link       http://phpbu.de/
  * @since      Class available since Release 2.1.12
  */
-class RedisCli extends Abstraction implements Executable
+class RedisCli extends Abstraction
 {
     use OptionMasker;
 
diff --git a/src/Cli/Executable/Rsync.php b/src/Cli/Executable/Rsync.php
index 02624b80..9e93723e 100644
--- a/src/Cli/Executable/Rsync.php
+++ b/src/Cli/Executable/Rsync.php
@@ -1,7 +1,6 @@
 <?php
 namespace phpbu\App\Cli\Executable;
 
-use phpbu\App\Cli\Executable;
 use phpbu\App\Exception;
 use SebastianFeldmann\Cli\CommandLine;
 use SebastianFeldmann\Cli\Command\Executable as Cmd;
@@ -17,7 +16,7 @@
  * @link       http://phpbu.de/
  * @since      Class available since Release 2.1.0
  */
-class Rsync extends Abstraction implements Executable
+class Rsync extends Abstraction
 {
     use OptionMasker;
 
diff --git a/src/Cli/Executable/Tar.php b/src/Cli/Executable/Tar.php
index 6e282df5..a8a36584 100644
--- a/src/Cli/Executable/Tar.php
+++ b/src/Cli/Executable/Tar.php
@@ -1,7 +1,6 @@
 <?php
 namespace phpbu\App\Cli\Executable;
 
-use phpbu\App\Cli\Executable;
 use phpbu\App\Exception;
 use SebastianFeldmann\Cli\CommandLine;
 use SebastianFeldmann\Cli\Command\Executable as Cmd;
@@ -17,7 +16,7 @@
  * @link       http://phpbu.de/
  * @since      Class available since Release 1.0.0
  */
-class Tar extends Abstraction implements Executable
+class Tar extends Abstraction
 {
     /**
      * Path to compress
diff --git a/src/Cli/Executable/Xtrabackup8.php b/src/Cli/Executable/Xtrabackup8.php
index 77bb3462..6d3151b5 100644
--- a/src/Cli/Executable/Xtrabackup8.php
+++ b/src/Cli/Executable/Xtrabackup8.php
@@ -1,7 +1,6 @@
 <?php
 namespace phpbu\App\Cli\Executable;
 
-use phpbu\App\Cli\Executable;
 use phpbu\App\Exception;
 use SebastianFeldmann\Cli\CommandLine;
 use SebastianFeldmann\Cli\Command\Executable as Cmd;
@@ -17,7 +16,7 @@
  * @link       http://phpbu.de/
  * @since      Class available since Release 6.0.10
  */
-class Xtrabackup8 extends Abstraction implements Executable
+class Xtrabackup8 extends Abstraction
 {
     use OptionMasker;
 
diff --git a/src/Configuration/Loader/Factory.php b/src/Configuration/Loader/Factory.php
index 7caf89b9..46f926f2 100644
--- a/src/Configuration/Loader/Factory.php
+++ b/src/Configuration/Loader/Factory.php
@@ -40,7 +40,7 @@ abstract class Factory
      * @param  \phpbu\App\Configuration\Bootstrapper $bootstrapper
      * @return \phpbu\App\Configuration\Loader
      */
-    public static function createLoader(string $filename, Bootstrapper $bootstrapper = null)
+    public static function createLoader(string $filename, ?Bootstrapper $bootstrapper = null)
     {
         $bs    = $bootstrapper ?? new Bootstrapper();
         $ext   = pathinfo($filename, PATHINFO_EXTENSION);