diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 14995b27d..36c7a36ef 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -21,11 +21,8 @@ jobs:
       fail-fast: false
       matrix:
         os-name: [ubuntu-22.04]
-        java-version: [11, 12, 13, 14, 15, 16, 17, 18, 19, 20]
+        java-version: [11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21-ea]
         include:
-          # Mockito doesn't yet support Java 21, so let's comment it out for now.
-          # - os-name: ubuntu-22.04
-          #   java-version: 21-ea
 
           # MacOS builds (only check Java 17).
           - os-name: macos-12
diff --git a/README.md b/README.md
index bda015a1e..ee8342f09 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-![Java 11+](https://img.shields.io/badge/Java-11--20-brown?logo=openjdk)
+![Java 11+](https://img.shields.io/badge/Java-11--21-brown?logo=openjdk)
 [![Build Status](https://github.com/ascopes/java-compiler-testing/actions/workflows/build.yml/badge.svg?branch=main)](https://github.com/ascopes/java-compiler-testing/actions/workflows/build.yml)
 [![Maven Central](https://img.shields.io/maven-central/v/io.github.ascopes.jct/java-compiler-testing)](https://repo1.maven.org/maven2/io/github/ascopes/jct/java-compiler-testing)
 [![Code Coverage](https://codecov.io/gh/ascopes/java-compiler-testing/branch/main/graph/badge.svg?token=VT74BP2742)](https://codecov.io/gh/ascopes/java-compiler-testing)
diff --git a/acceptance-tests/acceptance-tests-lombok/src/test/groovy/io/github/ascopes/jct/acceptancetests/lombok/LombokIntegrationTest.groovy b/acceptance-tests/acceptance-tests-lombok/src/test/groovy/io/github/ascopes/jct/acceptancetests/lombok/LombokIntegrationTest.groovy
index 5293d5360..7fafa6d88 100644
--- a/acceptance-tests/acceptance-tests-lombok/src/test/groovy/io/github/ascopes/jct/acceptancetests/lombok/LombokIntegrationTest.groovy
+++ b/acceptance-tests/acceptance-tests-lombok/src/test/groovy/io/github/ascopes/jct/acceptancetests/lombok/LombokIntegrationTest.groovy
@@ -18,9 +18,12 @@ package io.github.ascopes.jct.acceptancetests.lombok
 import io.github.ascopes.jct.compilers.JctCompiler
 import io.github.ascopes.jct.junit.JavacCompilerTest
 import io.github.ascopes.jct.workspaces.Workspaces
+import org.junit.jupiter.api.BeforeEach
 import org.junit.jupiter.api.DisplayName
+import org.junit.jupiter.api.condition.JRE
 
 import static io.github.ascopes.jct.assertions.JctAssertions.assertThatCompilation
+import static org.assertj.core.api.Assumptions.assumeThat
 import static org.assertj.core.api.SoftAssertions.assertSoftly
 
 /**
@@ -32,9 +35,16 @@ import static org.assertj.core.api.SoftAssertions.assertSoftly
  * @author Ashley Scopes
  */
 @DisplayName("Lombok Integration test")
-@SuppressWarnings('GrUnresolvedAccess')
+@SuppressWarnings("GrUnresolvedAccess")
 class LombokIntegrationTest {
 
+  @BeforeEach
+  void setUp() {
+    assumeThat(JRE.currentVersion())
+        .withFailMessage("Lombok fails under JDK-21: See Lombok GH-3393")
+        .isLessThanOrEqualTo(JRE.JAVA_20)
+  }
+
   @DisplayName("Lombok @Data compiles the expected data class")
   @JavacCompilerTest
   void lombokDataCompilesTheExpectedDataClass(JctCompiler compiler) {
diff --git a/pom.xml b/pom.xml
index 42fc5e1a0..b217935c4 100644
--- a/pom.xml
+++ b/pom.xml
@@ -141,8 +141,12 @@
 
       Tired compilation is modified to reduce the amount of time the JVM wastes JITing
       code during tests.
+
+      Byte Buddy experimental support enables running ByteBuddy (used by Mockito) in JDK
+      experimental builds.
     -->
     <argLine>
+      -Dnet.bytebuddy.experimental=true
       -Dorg.slf4j.simpleLogger.log=INFO
       -Dorg.slf4j.simpleLogger.log.io.github.ascopes.jct=TRACE
       -Xshare:off