diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 15cf15f..6a0e7b4 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -10,11 +10,11 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - name: Set up JDK 17
+      - name: Set up JDK 21
         uses: actions/setup-java@v4
         with:
           distribution: temurin
-          java-version: 17
+          java-version: 21
       - name: Run Spotless
         run: ./gradlew spotlessCheck
 
@@ -22,11 +22,11 @@ jobs:
     runs-on: macos-14
     steps:
       - uses: actions/checkout@v4
-      - name: Set up JDK 17
+      - name: Set up JDK 21
         uses: actions/setup-java@v4
         with:
           distribution: temurin
-          java-version: 17
+          java-version: 21
       - name: Setup Android problem matchers
         uses: jonasb/android-problem-matchers-action@v1
       - name: Build with Gradle
diff --git a/.idea/compiler.xml b/.idea/compiler.xml
index 4d4e5be..7a15fb6 100644
--- a/.idea/compiler.xml
+++ b/.idea/compiler.xml
@@ -11,7 +11,7 @@
       <entry name="!?*.kt" />
       <entry name="!?*.clj" />
     </wildcardResourcePatterns>
-    <bytecodeTargetLevel target="17">
+    <bytecodeTargetLevel target="21">
       <module name="Android.android-customtabs" target="11" />
     </bytecodeTargetLevel>
   </component>
diff --git a/customtabs-example/build.gradle.kts b/customtabs-example/build.gradle.kts
index 9ba8a7c..178cb6d 100644
--- a/customtabs-example/build.gradle.kts
+++ b/customtabs-example/build.gradle.kts
@@ -26,6 +26,8 @@ dependencies {
     implementation("com.google.android.material:material:1.12.0")
 }
 
+java.toolchain.languageVersion.set(JavaLanguageVersion.of(21))
+
 android {
     namespace = "com.example.saschpe.customtabs"
 
@@ -56,11 +58,4 @@ android {
             signingConfig = signingConfigs.getByName("debug")
         }
     }
-
-    compileOptions {
-        sourceCompatibility = JavaVersion.VERSION_17
-        targetCompatibility = JavaVersion.VERSION_17
-    }
-
-    kotlinOptions.jvmTarget = "17"
 }
diff --git a/customtabs/build.gradle.kts b/customtabs/build.gradle.kts
index e6ed85e..9df38ec 100644
--- a/customtabs/build.gradle.kts
+++ b/customtabs/build.gradle.kts
@@ -32,6 +32,8 @@ dependencies {
     testImplementation("org.mockito:mockito-core:5.13.0")
 }
 
+java.toolchain.languageVersion.set(JavaLanguageVersion.of(21))
+
 android {
     namespace = "saschpe.android.customtabs"
 
@@ -48,13 +50,6 @@ android {
         }
     }
 
-    compileOptions {
-        sourceCompatibility = JavaVersion.VERSION_17
-        targetCompatibility = JavaVersion.VERSION_17
-    }
-
-    kotlinOptions.jvmTarget = "17"
-
     testOptions.unitTests.isIncludeAndroidResources = true
 
     publishing {