diff --git a/build.gradle.kts b/build.gradle.kts
index e6582ce8..e01f345a 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -12,7 +12,7 @@ subprojects {
 
     java {
         toolchain {
-            languageVersion.set(JavaLanguageVersion.of(25))
+            languageVersion.set(JavaLanguageVersion.of(21))
         }
     }