diff --git a/scalabot-extension/build.gradle.kts b/scalabot-extension/build.gradle.kts
index 4e91eca..b11a614 100644
--- a/scalabot-extension/build.gradle.kts
+++ b/scalabot-extension/build.gradle.kts
@@ -23,6 +23,8 @@ tasks.withType<Javadoc> {
 java {
     withJavadocJar()
     withSourcesJar()
+    sourceCompatibility = JavaVersion.VERSION_11
+    targetCompatibility = JavaVersion.VERSION_11
 }
 
 tasks.test {