diff --git a/src/Standards/Typo3Update/Sniffs/Deprecated/AjaxRegistrationSniff.php b/src/Standards/Typo3Update/Sniffs/Deprecated/AjaxRegistrationSniff.php
new file mode 100644
index 0000000..73a2061
--- /dev/null
+++ b/src/Standards/Typo3Update/Sniffs/Deprecated/AjaxRegistrationSniff.php
@@ -0,0 +1,96 @@
+<?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 PhpCsTokens;
+
+/**
+ */
+class Typo3Update_Sniffs_Deprecated_AjaxRegistrationSniff implements PhpCsSniff
+{
+    /**
+     * Defines files to check.
+     * As soon as PHP_CS 3 is used, define them in ruleset.xml.
+     *
+     * @var array<string>
+     */
+    public $filenamesToCheck = [
+        'ext_tables.php',
+        'ext_localconf.php',
+    ];
+
+    /**
+     * Returns the token types that this sniff is interested in.
+     *
+     * @return array<int>
+     */
+    public function register()
+    {
+        return PhpCsTokens::$stringTokens;
+    }
+
+    /**
+     * 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, $stackPtr)
+    {
+        if (in_array(basename($phpcsFile->getFilename()), $this->filenamesToCheck) === false) {
+            return;
+        }
+
+        $tokens = $phpcsFile->getTokens();
+        if ($tokens[$stackPtr]['content'] !== "'AJAX'") {
+            return;
+        }
+        $equalSign = $phpcsFile->findNext(T_EQUAL, $stackPtr, null, false, null, true);
+        if ($equalSign === false) {
+            return;
+        }
+        $tokenToCheck = $phpcsFile->findNext(T_WHITESPACE, $equalSign + 1, null, true, null, true);
+        if ($tokenToCheck === false) {
+            return;
+        }
+        $token = $tokens[$tokenToCheck];
+        if ($token['code'] !== T_CONSTANT_ENCAPSED_STRING) {
+            return;
+        }
+
+        $phpcsFile->addWarning(
+            "Defining AJAX using %s is no longer supported with a single String like %s.\n"
+            . "Since TYPO3 7.6, use PSR-7-based Routing for Backend AJAX Requests.\n"
+            . 'See: %s',
+            $tokenToCheck,
+            '',
+            [
+                "\$GLOBALS['TYPO3_CONF_VARS']['BE']['AJAX'][\$ajaxID]",
+                $token['content'],
+                'https://docs.typo3.org/typo3cms/extensions/core/Changelog/7.6/Feature-69916-PSR-7-basedRoutingForBackendAJAXRequests.html'
+            ]
+        );
+    }
+}