diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 5e436abd95..ac03e6d1af 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -49,6 +49,9 @@ jobs:
           - kind: maven
             jre: 11
             os: windows-latest
+          - kind: maven
+            jre: 21
+            os: ubuntu-latest
           - kind: gradle
             jre: 17
             os: windows-latest
diff --git a/CHANGES.md b/CHANGES.md
index d5443669a0..372483551e 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -10,6 +10,10 @@ This document is intended for Spotless developers.
 We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (starting after version `1.27.0`).
 
 ## [Unreleased]
+###
+* Bump palantir-java-format to 2.38.0 ([#1822](https://github.com/diffplug/spotless/pull/1822))
+### Added
+* Add Java 21 to CI ([#1822](https://github.com/diffplug/spotless/pull/1822))
 
 ## [2.43.0] - 2023-11-27
 ### Added
diff --git a/lib/src/main/java/com/diffplug/spotless/java/PalantirJavaFormatStep.java b/lib/src/main/java/com/diffplug/spotless/java/PalantirJavaFormatStep.java
index f769ad09ec..2c3b84c40d 100644
--- a/lib/src/main/java/com/diffplug/spotless/java/PalantirJavaFormatStep.java
+++ b/lib/src/main/java/com/diffplug/spotless/java/PalantirJavaFormatStep.java
@@ -30,7 +30,7 @@ private PalantirJavaFormatStep() {}
 	private static final String DEFAULT_STYLE = "PALANTIR";
 	private static final String NAME = "palantir-java-format";
 	private static final String MAVEN_COORDINATE = "com.palantir.javaformat:palantir-java-format:";
-	private static final Jvm.Support<String> JVM_SUPPORT = Jvm.<String> support(NAME).add(8, "1.1.0").add(11, "2.28.0");
+	private static final Jvm.Support<String> JVM_SUPPORT = Jvm.<String> support(NAME).add(8, "1.1.0").add(11, "2.28.0").add(21, "2.38.0");
 
 	/** Creates a step which formats everything - code, import order, and unused imports. */
 	public static FormatterStep create(Provisioner provisioner) {
diff --git a/plugin-gradle/src/main/java/com/diffplug/gradle/spotless/GradleProvisioner.java b/plugin-gradle/src/main/java/com/diffplug/gradle/spotless/GradleProvisioner.java
index 288cc10c72..dd5a55ba8b 100644
--- a/plugin-gradle/src/main/java/com/diffplug/gradle/spotless/GradleProvisioner.java
+++ b/plugin-gradle/src/main/java/com/diffplug/gradle/spotless/GradleProvisioner.java
@@ -28,7 +28,9 @@
 import org.gradle.api.artifacts.dsl.DependencyHandler;
 import org.gradle.api.attributes.Bundling;
 import org.gradle.api.attributes.Category;
+import org.gradle.api.attributes.java.TargetJvmEnvironment;
 import org.gradle.api.initialization.dsl.ScriptHandler;
+import org.gradle.util.GradleVersion;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -124,6 +126,10 @@ private static Provisioner forConfigurationContainer(Project project, Configurat
 				config.attributes(attr -> {
 					attr.attribute(Category.CATEGORY_ATTRIBUTE, project.getObjects().named(Category.class, Category.LIBRARY));
 					attr.attribute(Bundling.BUNDLING_ATTRIBUTE, project.getObjects().named(Bundling.class, Bundling.EXTERNAL));
+					// TARGET_JVM_ENVIRONMENT_ATTRIBUTE has been added in Gradle 7.0
+					if (GradleVersion.current().compareTo(GradleVersion.version(SpotlessPlugin.VER_GRADLE_7)) >= 0) {
+						attr.attribute(TargetJvmEnvironment.TARGET_JVM_ENVIRONMENT_ATTRIBUTE, project.getObjects().named(TargetJvmEnvironment.class, TargetJvmEnvironment.STANDARD_JVM));
+					}
 				});
 				return config.resolve();
 			} catch (Exception e) {
diff --git a/plugin-gradle/src/main/java/com/diffplug/gradle/spotless/SpotlessPlugin.java b/plugin-gradle/src/main/java/com/diffplug/gradle/spotless/SpotlessPlugin.java
index 0043e2b274..4e01d98eb3 100644
--- a/plugin-gradle/src/main/java/com/diffplug/gradle/spotless/SpotlessPlugin.java
+++ b/plugin-gradle/src/main/java/com/diffplug/gradle/spotless/SpotlessPlugin.java
@@ -27,6 +27,7 @@
 public class SpotlessPlugin implements Plugin<Project> {
 	static final String SPOTLESS_MODERN = "spotlessModern";
 	static final String VER_GRADLE_min = "6.1.1";
+	static final String VER_GRADLE_7 = "7.0";
 	static final String VER_GRADLE_javaPluginExtension = "7.1";
 	private static final int MINIMUM_JRE = 11;
 
diff --git a/testlib/src/main/java/com/diffplug/spotless/TestProvisioner.java b/testlib/src/main/java/com/diffplug/spotless/TestProvisioner.java
index 7c7b7b67f7..0575e35350 100644
--- a/testlib/src/main/java/com/diffplug/spotless/TestProvisioner.java
+++ b/testlib/src/main/java/com/diffplug/spotless/TestProvisioner.java
@@ -33,7 +33,9 @@
 import org.gradle.api.artifacts.dsl.RepositoryHandler;
 import org.gradle.api.attributes.Bundling;
 import org.gradle.api.attributes.Category;
+import org.gradle.api.attributes.java.TargetJvmEnvironment;
 import org.gradle.testfixtures.ProjectBuilder;
+import org.gradle.util.GradleVersion;
 
 import com.diffplug.common.base.Errors;
 import com.diffplug.common.base.StandardSystemProperty;
@@ -73,6 +75,10 @@ private static Provisioner createWithRepositories(Consumer<RepositoryHandler> re
 			config.attributes(attr -> {
 				attr.attribute(Category.CATEGORY_ATTRIBUTE, project.getObjects().named(Category.class, Category.LIBRARY));
 				attr.attribute(Bundling.BUNDLING_ATTRIBUTE, project.getObjects().named(Bundling.class, Bundling.EXTERNAL));
+				// TARGET_JVM_ENVIRONMENT_ATTRIBUTE has been added in Gradle 7.0
+				if (GradleVersion.current().compareTo(GradleVersion.version("7.0")) >= 0) {
+					attr.attribute(TargetJvmEnvironment.TARGET_JVM_ENVIRONMENT_ATTRIBUTE, project.getObjects().named(TargetJvmEnvironment.class, TargetJvmEnvironment.STANDARD_JVM));
+				}
 			});
 			try {
 				return config.resolve();