diff --git a/build.gradle.kts b/build.gradle.kts
index a0bb894..feb6bff 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -18,13 +18,21 @@ repositories {
     mavenCentral()
 }
 
+java {
+    sourceCompatibility = JavaVersion.VERSION_1_8
+    targetCompatibility = JavaVersion.VERSION_1_8
+}
+
 kotlin {
     jvm {
         withJava()
+        compilations.all {
+            kotlinOptions {
+                jvmTarget = "1.8"
+            }
+        }
     }
 
-    jvmToolchain(8)
-
     js(IR) {
         browser {}
         binaries.executable()