diff --git a/src/Query/Parser.php b/src/Query/Parser.php
index a76cd4e45a..5d0742b4a3 100644
--- a/src/Query/Parser.php
+++ b/src/Query/Parser.php
@@ -200,6 +200,13 @@ public function __construct(Query $query)
      */
     public function setCustomOutputTreeWalker($className)
     {
+        Deprecation::trigger(
+            'doctrine/orm',
+            'https://github.com/doctrine/orm/pull/11641',
+            '%s is deprecated, set the output walker class in a query hint instead',
+            __METHOD__
+        );
+
         $this->customOutputWalker = $className;
     }
 
diff --git a/tests/Tests/ORM/Query/LanguageRecognitionTest.php b/tests/Tests/ORM/Query/LanguageRecognitionTest.php
index a2e0e60096..37aac27f26 100644
--- a/tests/Tests/ORM/Query/LanguageRecognitionTest.php
+++ b/tests/Tests/ORM/Query/LanguageRecognitionTest.php
@@ -51,7 +51,7 @@ public function parseDql(string $dql, array $hints = []): ParserResult
         $parser = new Query\Parser($query);
 
         // We do NOT test SQL output here. That only unnecessarily slows down the tests!
-        $parser->setCustomOutputTreeWalker(NullSqlWalker::class);
+        $query->setHint(Query::HINT_CUSTOM_OUTPUT_WALKER, NullSqlWalker::class);
 
         return $parser->parse();
     }