diff --git a/core/library/build.gradle b/core/library/build.gradle
index 6f63a004..0a7ec71e 100644
--- a/core/library/build.gradle
+++ b/core/library/build.gradle
@@ -6,6 +6,13 @@ android {
         baselineFile file("lint-baseline.xml")
         abortOnError true
     }
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
+    kotlinOptions {
+        jvmTarget = '1.8'
+    }
 }
 
 dependencies {
diff --git a/core/subsonic-api-image-loader/build.gradle b/core/subsonic-api-image-loader/build.gradle
index 72736d35..dc8324b7 100644
--- a/core/subsonic-api-image-loader/build.gradle
+++ b/core/subsonic-api-image-loader/build.gradle
@@ -4,6 +4,13 @@ android {
     buildFeatures {
         buildConfig = true
     }
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
+    kotlinOptions {
+        jvmTarget = '1.8'
+    }
 }
 
 dependencies {
diff --git a/gradle_scripts/android-module-bootstrap.gradle b/gradle_scripts/android-module-bootstrap.gradle
index 96a26cc9..bea1ddaa 100644
--- a/gradle_scripts/android-module-bootstrap.gradle
+++ b/gradle_scripts/android-module-bootstrap.gradle
@@ -17,7 +17,12 @@ android {
         targetSdkVersion versions.targetSdk
     }
 
+    kotlinOptions {
+        jvmTarget = "1.8"
+    }
+
     compileOptions {
+        // Sets Java compatibility to Java 8
         sourceCompatibility JavaVersion.VERSION_1_8
         targetCompatibility JavaVersion.VERSION_1_8
     }
@@ -44,8 +49,6 @@ android {
     }
 }
 
-sourceCompatibility = JavaVersion.VERSION_1_8
-targetCompatibility = JavaVersion.VERSION_1_8
 
 tasks.withType(Test) {
     useJUnitPlatform()
diff --git a/gradle_scripts/kotlin-module-bootstrap.gradle b/gradle_scripts/kotlin-module-bootstrap.gradle
index 1c406a2a..7dc53a05 100644
--- a/gradle_scripts/kotlin-module-bootstrap.gradle
+++ b/gradle_scripts/kotlin-module-bootstrap.gradle
@@ -3,9 +3,6 @@ apply plugin: 'kotlin'
 apply plugin: 'jacoco'
 apply from: "${project.rootDir}/gradle_scripts/code_quality.gradle"
 
-sourceCompatibility = JavaVersion.VERSION_1_8
-targetCompatibility = JavaVersion.VERSION_1_8
-
 sourceSets {
     main.java.srcDirs += "${projectDir}/src/main/kotlin"
     test.java.srcDirs += "${projectDir}/src/test/kotlin"
diff --git a/ultrasonic/build.gradle b/ultrasonic/build.gradle
index 6c64e17a..a1a1b99d 100644
--- a/ultrasonic/build.gradle
+++ b/ultrasonic/build.gradle
@@ -54,6 +54,10 @@ android {
     kotlinOptions {
         jvmTarget = "1.8"
     }
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
 }
 
 tasks.withType(Test) {