diff --git a/komga/build.gradle.kts b/komga/build.gradle.kts
index 62acd830a..5abdca3d3 100644
--- a/komga/build.gradle.kts
+++ b/komga/build.gradle.kts
@@ -112,6 +112,10 @@ dependencies {
 
 val webui = "$rootDir/komga-webui"
 tasks {
+  withType<JavaCompile> {
+    sourceCompatibility = "1.8"
+    targetCompatibility = "1.8"
+  }
   withType<KotlinCompile> {
     kotlinOptions {
       jvmTarget = "1.8"