diff -r 822b7e3d064d -r b3f14cd4f3ab build.gradle.kts
--- a/build.gradle.kts	Fri Oct 23 20:34:57 2020 +0200
+++ b/build.gradle.kts	Sat Oct 24 12:09:08 2020 +0200
@@ -1,3 +1,4 @@
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 
 plugins {
     kotlin("jvm") version "1.4.10"
@@ -13,6 +14,10 @@
     mavenCentral()
 }
 
+tasks.withType<KotlinCompile>().configureEach {
+    kotlinOptions.jvmTarget = "11"
+}
+
 tasks.war {
     archiveFileName.set("lightpit.war")
     from("src/main/resources")