diff --git a/build.gradle.kts b/build.gradle.kts
index 616408a97..915bd0b6c 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -312,7 +312,7 @@ tasks {
 			javadocTool.set(project.javaToolchains.javadocToolFor {
 				// create Javadoc with least Java version to get all features
 				// (e.g. search result page on 20)
-				languageVersion.set(JavaLanguageVersion.of(20))
+				languageVersion.set(JavaLanguageVersion.of(21))
 			})
 		}