diff --git a/.github/workflows/java-all-versions.yml b/.github/workflows/java-all-versions.yml
index 9f089785f..f0162691b 100644
--- a/.github/workflows/java-all-versions.yml
+++ b/.github/workflows/java-all-versions.yml
@@ -1,4 +1,4 @@
-name: Java 8, 11, 17, 21 CI
+name: Java 21 CI
 
 on: [push,pull_request]
 
@@ -8,24 +8,14 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
-      - name: Set up JDKs 8, 11, 17, 21
+      - name: Set up JDK 21
         uses: actions/setup-java@v4
         with:
           distribution: 'temurin'
-          java-version: |
-            8
-            11
-            17
-            21
+          java-version: 21
       - name: Build with Gradle
         run: ./gradlew assemble
       - name: Style check
         run: ./gradlew checkstyleMain
-      - name: Test with Java 8
-        run: ./gradlew test -PtestOnJava=8 --stacktrace
-      - name: Test with Java 11
-        run: ./gradlew test -PtestOnJava=11 --stacktrace
-      - name: Test with Java 17
-        run: ./gradlew test -PtestOnJava=17 --stacktrace
       - name: Test with Java 21
         run: ./gradlew test -PtestOnJava=21 --stacktrace
diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
index 4b0c0b390..4445312c5 100644
--- a/.github/workflows/macos.yml
+++ b/.github/workflows/macos.yml
@@ -1,4 +1,4 @@
-name: Java 11 CI macOS (Apple)
+name: Java 21 CI macOS (Apple)
 
 on:
   push:
@@ -10,11 +10,11 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
-      - name: Set up JDK 11
+      - name: Set up JDK 21
         uses: actions/setup-java@v4
         with:
           distribution: 'temurin'
-          java-version: 11
+          java-version: 21
       - name: Build with Gradle
         run: ./gradlew assemble
       - name: Test with Gradle
diff --git a/RoaringBitmap/build.gradle.kts b/RoaringBitmap/build.gradle.kts
index b9beaf5a3..13868e6fc 100644
--- a/RoaringBitmap/build.gradle.kts
+++ b/RoaringBitmap/build.gradle.kts
@@ -27,7 +27,7 @@ tasks.named<Jar>("sourcesJar") {
 // Unset Java 8 release applied from root project to allow modularity plugin to
 // control the class file versions.
 tasks.named<JavaCompile>("compileJava") {
-    options.release.set(null as Int?)
+    options.release.set(21)
 }
 
 configure<org.javamodularity.moduleplugin.extensions.ModularityExtension> {
@@ -37,7 +37,7 @@ configure<org.javamodularity.moduleplugin.extensions.ModularityExtension> {
 // Unset Java 8 release applied from root project to allow modularity plugin to
 // control the class file versions.
 tasks.named<JavaCompile>("compileModuleInfoJava") {
-    options.release.set(null as Int?)
+    options.release.set(21)
 }
 
 tasks.test {
diff --git a/build.gradle.kts b/build.gradle.kts
index 7efd6c644..18a374d64 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -33,7 +33,7 @@ subprojects {
             options.isDeprecation = true
             options.isWarnings = true
             options.compilerArgs = listOf("-Xlint:unchecked")
-            options.release.set(8)
+            options.release.set(21)
         }
 
         withType<Javadoc> {