diff --git a/src/Standards/Typo3Update/Sniffs/LegacyClassnames/AbstractClassnameChecker.php b/src/Standards/Typo3Update/Sniffs/LegacyClassnames/AbstractClassnameChecker.php
index 218ccee..a01da60 100644
--- a/src/Standards/Typo3Update/Sniffs/LegacyClassnames/AbstractClassnameChecker.php
+++ b/src/Standards/Typo3Update/Sniffs/LegacyClassnames/AbstractClassnameChecker.php
@@ -43,6 +43,11 @@ abstract class AbstractClassnameChecker implements PhpCsSniff
      */
     public $legacyExtensions = ['Extbase', 'Fluid'];
 
+    /**
+     * @var Mapping
+     */
+    protected $legacyMapping;
+
     public function __construct()
     {
         $this->legacyMapping = Mapping::getInstance();
@@ -205,6 +210,7 @@ abstract class AbstractClassnameChecker implements PhpCsSniff
      * @param PhpCsFile $phpcsFile
      * @param int $classnamePosition
      * @param string $classname
+     * @param bool $forceEmptyPrefix Defines whether '\\' prefix should be checked or always be left out.
      */
     protected function replaceLegacyClassname(PhpCsFile $phpcsFile, $classnamePosition, $classname, $forceEmptyPrefix = false)
     {
diff --git a/src/Standards/Typo3Update/Sniffs/LegacyClassnames/Mapping.php b/src/Standards/Typo3Update/Sniffs/LegacyClassnames/Mapping.php
index e704584..c7c455e 100644
--- a/src/Standards/Typo3Update/Sniffs/LegacyClassnames/Mapping.php
+++ b/src/Standards/Typo3Update/Sniffs/LegacyClassnames/Mapping.php
@@ -50,9 +50,7 @@ class Mapping
     }
     private function __construct()
     {
-        $mappingFile = $this->getMappingFile();
-
-        $this->mappings = require $mappingFile;
+        $this->mappings = require $this->getMappingFile();
     }
     // Singleton implementation - End
 
@@ -112,10 +110,8 @@ class Mapping
             return;
         }
 
-        $mappingFile = $this->getMappingFile();
-
         file_put_contents(
-            $mappingFile,
+            $this->getMappingFile(),
             '<?php' . PHP_EOL . 'return ' . var_export($this->mappings, true) . ';'
         );
     }
diff --git a/src/Standards/Typo3Update/Sniffs/LegacyClassnames/MissingNamespaceSniff.php b/src/Standards/Typo3Update/Sniffs/LegacyClassnames/MissingNamespaceSniff.php
index 5374dd3..3e3acac 100644
--- a/src/Standards/Typo3Update/Sniffs/LegacyClassnames/MissingNamespaceSniff.php
+++ b/src/Standards/Typo3Update/Sniffs/LegacyClassnames/MissingNamespaceSniff.php
@@ -92,6 +92,7 @@ class Typo3Update_Sniffs_LegacyClassnames_MissingNamespaceSniff extends Abstract
      * @param PhpCsFile $phpcsFile
      * @param int $classnamePosition
      * @param string $classname
+     * @param bool $forceEmptyPrefix Defines whether '\\' prefix should be checked or always be left out.
      */
     protected function replaceLegacyClassname(PhpCsFile $phpcsFile, $classnamePosition, $classname, $forceEmptyPrefix = true)
     {
@@ -138,9 +139,9 @@ class Typo3Update_Sniffs_LegacyClassnames_MissingNamespaceSniff extends Abstract
     }
 
     /**
-     * Returns namespace, without vendor, based on legacy class name.
+     * Returns namespace, based on legacy class name.
      *
-     * E.g. Tx_ExtName_FolderName_FileName -> ExtName\FolderName
+     * E.g. Tx_ExtName_FolderName_FileName -> VENDOR\ExtName\FolderName
      *
      * @param string $classname
      * @return string
diff --git a/src/Standards/Typo3Update/Sniffs/LegacyClassnames/MissingVendorForPluginsAndModulesSniff.php b/src/Standards/Typo3Update/Sniffs/LegacyClassnames/MissingVendorForPluginsAndModulesSniff.php
index 072bf62..4c76a90 100644
--- a/src/Standards/Typo3Update/Sniffs/LegacyClassnames/MissingVendorForPluginsAndModulesSniff.php
+++ b/src/Standards/Typo3Update/Sniffs/LegacyClassnames/MissingVendorForPluginsAndModulesSniff.php
@@ -84,7 +84,7 @@ class Typo3Update_Sniffs_LegacyClassnames_MissingVendorForPluginsAndModulesSniff
         if ($fix === true) {
             $phpcsFile->fixer->replaceToken(
                 $firstArgument,
-                "'{$this->getVendor()}.' . " . $tokens[$firstArgument]['content']
+                "'{$this->getVendor()}.' . {$tokens[$firstArgument]['content']}"
             );
         }
     }