diff --git a/src/Standards/Typo3Update/Sniffs/LegacyClassnames/AbstractClassnameChecker.php b/src/Standards/Typo3Update/Sniffs/LegacyClassnames/AbstractClassnameChecker.php
index 57668a3..6019cdc 100644
--- a/src/Standards/Typo3Update/Sniffs/LegacyClassnames/AbstractClassnameChecker.php
+++ b/src/Standards/Typo3Update/Sniffs/LegacyClassnames/AbstractClassnameChecker.php
@@ -20,15 +20,17 @@ namespace Typo3Update\Sniffs\LegacyClassnames;
  * 02110-1301, USA.
  */
 
-use PHP_CodeSniffer as PhpCs;
 use PHP_CodeSniffer_File as PhpCsFile;
 use PHP_CodeSniffer_Sniff as PhpCsSniff;
+use Typo3Update\Sniffs\OptionsAccessTrait;
 
 /**
  * Provide common uses for all sniffs, regarding class name checks.
  */
 abstract class AbstractClassnameChecker implements PhpCsSniff
 {
+    use OptionsAccessTrait;
+
     /**
      * Contains mapping from old -> new class names.
      * @var array
@@ -45,20 +47,6 @@ abstract class AbstractClassnameChecker implements PhpCsSniff
      */
     public $legacyExtensions = ['Extbase', 'Fluid'];
 
-    /**
-     * Returns the configured vendor, e.g. to generate new namespaces.
-     *
-     * @return string
-     */
-    protected function getVendor()
-    {
-        $vendor = PhpCs::getConfigData('vendor');
-        if (!$vendor) {
-            $vendor = 'YourCompany';
-        }
-        return trim($vendor, '\\/');
-    }
-
     /**
      * @param string $mappingFile File containing php array for mapping.
      */
diff --git a/src/Standards/Typo3Update/Sniffs/LegacyClassnames/MissingVendorForPluginsAndModulesSniff.php b/src/Standards/Typo3Update/Sniffs/LegacyClassnames/MissingVendorForPluginsAndModulesSniff.php
new file mode 100644
index 0000000..e2fc43b
--- /dev/null
+++ b/src/Standards/Typo3Update/Sniffs/LegacyClassnames/MissingVendorForPluginsAndModulesSniff.php
@@ -0,0 +1,89 @@
+<?php
+
+/*
+ * Copyright (C) 2017  Daniel Siepmann <coding@daniel-siepmann.de>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+use PHP_CodeSniffer_File as PhpCsFile;
+use PHP_CodeSniffer_Sniff as PhpCsSniff;
+use PHP_CodeSniffer_Tokens as Tokens;
+
+/**
+ * Detect whether vendor is missing for plugins and modules registrations and configurations.
+ */
+class Typo3Update_Sniffs_LegacyClassnames_MissingVendorForPluginsAndModulesSniff implements PhpCsSniff
+{
+    use \Typo3Update\Sniffs\ExtendedPhpCsSupportTrait;
+    use \Typo3Update\Sniffs\OptionsAccessTrait;
+
+    /**
+     * Original token content for reuse accross methods.
+     * @var string
+     */
+    protected $originalTokenContent = '';
+
+    /**
+     * Returns the token types that this sniff is interested in.
+     *
+     * @return array<int>
+     */
+    public function register()
+    {
+        return Tokens::$functionNameTokens;
+    }
+
+    /**
+     * Processes the tokens that this sniff is interested in.
+     *
+     * @param PhpCsFile $phpcsFile The file where the token was found.
+     * @param int                  $stackPtr  The position in the stack where
+     *                                        the token was found.
+     *
+     * @return void
+     */
+    public function process(PhpCsFile $phpcsFile, $stackPtr)
+    {
+        $functionsToHandle = ['registerPlugin', 'configurePlugin', 'registerModule', 'configureModule'];
+        if (!$this->isFunctionCall($phpcsFile, $stackPtr)) {
+            return;
+        }
+        $tokens = $phpcsFile->getTokens();
+
+        if (!in_array($tokens[$stackPtr]['content'], $functionsToHandle)) {
+            return;
+        }
+
+        $firstParameter = $phpcsFile->findNext([T_WHITESPACE, T_OPEN_PARENTHESIS], $stackPtr + 1, null, true);
+        if ($firstParameter === false || $tokens[$firstParameter]['code'] === T_CONSTANT_ENCAPSED_STRING) {
+            return;
+        }
+
+        $fix = $phpcsFile->addFixableError(
+            'No vendor is given, that will break TYPO3 handling for namespaced classes. Add vendor before Extensionkey like: "Vendor." . $_EXTKEY',
+            $firstParameter,
+            'missingVendor'
+        );
+
+        if ($fix === true) {
+            $phpcsFile->fixer->replaceToken(
+                $firstParameter,
+                "'{$this->getVendor()}.' . " . $tokens[$firstParameter]['content']
+            );
+        }
+    }
+}
diff --git a/src/Standards/Typo3Update/Sniffs/OptionsAccessTrait.php b/src/Standards/Typo3Update/Sniffs/OptionsAccessTrait.php
new file mode 100644
index 0000000..3037bd8
--- /dev/null
+++ b/src/Standards/Typo3Update/Sniffs/OptionsAccessTrait.php
@@ -0,0 +1,43 @@
+<?php
+namespace Typo3Update\Sniffs;
+
+/*
+ * Copyright (C) 2017  Daniel Siepmann <coding@daniel-siepmann.de>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+use PHP_CodeSniffer as PhpCs;
+
+/**
+ * Wrapper to retrieve options from PhpCs with defaults.
+ */
+trait OptionsAccessTrait
+{
+    /**
+     * Returns the configured vendor, e.g. to generate new namespaces.
+     *
+     * @return string
+     */
+    public function getVendor()
+    {
+        $vendor = PhpCs::getConfigData('vendor');
+        if (!$vendor) {
+            $vendor = 'YourCompany';
+        }
+        return trim($vendor, '\\/');
+    }
+}