diff --git a/RELEASE-NOTES-1.42 b/RELEASE-NOTES-1.42
index d7c75c4ff96..5f7f42ca47f 100644
--- a/RELEASE-NOTES-1.42
+++ b/RELEASE-NOTES-1.42
@@ -108,6 +108,7 @@ because of Phabricator reports.
   Vuex 4 will remain accessible for the foreseeable future. Pinia should be used
   for new projects.
 * Title::getBrokenLinksFrom() has been deprecated.
+* ParserOutput::setLanguageLinks() has been deprecated.
 * …
 
 === Other changes in 1.42 ===
diff --git a/includes/parser/ParserOutput.php b/includes/parser/ParserOutput.php
index 15e2ea05574..bc826d11c37 100644
--- a/includes/parser/ParserOutput.php
+++ b/includes/parser/ParserOutput.php
@@ -810,6 +810,9 @@ class ParserOutput extends CacheTime implements ContentMetadataCollector {
 		return wfSetVar( $this->mText, $text, true );
 	}
 
+	/**
+	 * @deprecated since 1.42, use ::addLanguageLink() instead.
+	 */
 	public function setLanguageLinks( $ll ) {
 		return wfSetVar( $this->mLanguageLinks, $ll );
 	}