diff --git a/app/build.gradle b/app/build.gradle
index 1a4cfda9..09291b04 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -38,11 +38,11 @@ android {
         abortOnError true
     }
     compileOptions {
-        targetCompatibility 1.8
-        sourceCompatibility 1.8
+        sourceCompatibility = JavaVersion.VERSION_11
+        targetCompatibility = JavaVersion.VERSION_11
     }
     kotlinOptions {
-        jvmTarget = JavaVersion.VERSION_1_8.toString()
+        jvmTarget = JavaVersion.VERSION_11.toString()
         languageVersion = "1.6"
     }
     testOptions {
@@ -159,9 +159,6 @@ apply from: "${rootProject.rootDir}/gradle/ktlint.gradle"
 
 gradle.projectsEvaluated {
     tasks.withType(JavaCompile) {
-        if (JavaVersion.current() >= JavaVersion.VERSION_1_9) {
-            options.compilerArgs.addAll(['--release', '8'])
-        }
         options.compilerArgs.add('-Xbootclasspath/p:app/libs/android.jar:app/libs/libcore.jar')
     }
 }
diff --git a/contactsbackup/build.gradle b/contactsbackup/build.gradle
index c7999696..71121216 100644
--- a/contactsbackup/build.gradle
+++ b/contactsbackup/build.gradle
@@ -15,12 +15,12 @@ android {
     }
 
     compileOptions {
-        sourceCompatibility = 1.8
-        targetCompatibility = 1.8
+        sourceCompatibility = JavaVersion.VERSION_11
+        targetCompatibility = JavaVersion.VERSION_11
     }
 
     kotlinOptions {
-        jvmTarget = '1.8'
+        jvmTarget = JavaVersion.VERSION_11.toString()
     }
 
     testOptions {
diff --git a/storage/demo/build.gradle b/storage/demo/build.gradle
index 6950ebc8..c99f2060 100644
--- a/storage/demo/build.gradle
+++ b/storage/demo/build.gradle
@@ -27,11 +27,11 @@ android {
         }
     }
     compileOptions {
-        sourceCompatibility JavaVersion.VERSION_1_8
-        targetCompatibility JavaVersion.VERSION_1_8
+        sourceCompatibility = JavaVersion.VERSION_11
+        targetCompatibility = JavaVersion.VERSION_11
     }
     kotlinOptions {
-        jvmTarget = '1.8'
+        jvmTarget = JavaVersion.VERSION_11.toString()
         freeCompilerArgs += "-Xopt-in=kotlin.RequiresOptIn"
     }
     lintOptions {
diff --git a/storage/lib/build.gradle b/storage/lib/build.gradle
index 1860c9af..ae711395 100644
--- a/storage/lib/build.gradle
+++ b/storage/lib/build.gradle
@@ -28,11 +28,11 @@ android {
         }
     }
     compileOptions {
-        sourceCompatibility JavaVersion.VERSION_1_8
-        targetCompatibility JavaVersion.VERSION_1_8
+        sourceCompatibility = JavaVersion.VERSION_11
+        targetCompatibility = JavaVersion.VERSION_11
     }
     kotlinOptions {
-        jvmTarget = '1.8'
+        jvmTarget = JavaVersion.VERSION_11.toString()
         languageVersion = "1.6"
         freeCompilerArgs += '-Xopt-in=kotlin.RequiresOptIn'
         freeCompilerArgs += '-Xexplicit-api=strict'