diff --git a/initializr-service/src/main/java/io/spring/initializr/service/extension/Java9RequestPostProcessor.java b/initializr-service/src/main/java/io/spring/initializr/service/extension/Java9RequestPostProcessor.java
new file mode 100644
index 00000000..084c32fb
--- /dev/null
+++ b/initializr-service/src/main/java/io/spring/initializr/service/extension/Java9RequestPostProcessor.java
@@ -0,0 +1,57 @@
+/*
+ * Copyright 2012-2017 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.spring.initializr.service.extension;
+
+import java.util.Arrays;
+import java.util.List;
+
+import io.spring.initializr.generator.ProjectRequest;
+import io.spring.initializr.generator.ProjectRequestPostProcessor;
+import io.spring.initializr.metadata.InitializrMetadata;
+import io.spring.initializr.util.Version;
+
+import org.springframework.stereotype.Component;
+
+/**
+ * Handle corner cases when Java9 is required.
+ *
+ * @author Stephane Nicoll
+ */
+@Component
+class Java9RequestPostProcessor implements ProjectRequestPostProcessor {
+
+	private static final Version VERSION_2_0_0_M1 = Version.parse("2.0.0.M1");
+
+	private static final List<String> UNSUPPORTED_LANGUAGES = Arrays.asList("groovy", "kotlin");
+
+	@Override
+	public void postProcessAfterResolution(ProjectRequest request, InitializrMetadata metadata) {
+		Version requestVersion = Version.safeParse(request.getBootVersion());
+		if (!"9".equals(request.getJavaVersion())) {
+			return;
+		}
+		// Not supported for Spring Boot 1.x
+		if (VERSION_2_0_0_M1.compareTo(requestVersion) > 0) {
+			request.setJavaVersion("1.8");
+		}
+		// Not supported for Kotlin & Groovy
+		if (UNSUPPORTED_LANGUAGES.contains(request.getLanguage())) {
+			request.setJavaVersion("1.8");
+		}
+	}
+
+}
diff --git a/initializr-service/src/main/java/io/spring/initializr/service/extension/SpringBoot2RequestPostProcessor.java b/initializr-service/src/main/java/io/spring/initializr/service/extension/SpringBoot2RequestPostProcessor.java
index c76879e5..da5513ed 100644
--- a/initializr-service/src/main/java/io/spring/initializr/service/extension/SpringBoot2RequestPostProcessor.java
+++ b/initializr-service/src/main/java/io/spring/initializr/service/extension/SpringBoot2RequestPostProcessor.java
@@ -16,6 +16,9 @@
 
 package io.spring.initializr.service.extension;
 
+import java.util.Arrays;
+import java.util.List;
+
 import io.spring.initializr.generator.ProjectRequest;
 import io.spring.initializr.generator.ProjectRequestPostProcessor;
 import io.spring.initializr.metadata.InitializrMetadata;
@@ -34,11 +37,15 @@ class SpringBoot2RequestPostProcessor implements ProjectRequestPostProcessor {
 
 	private static final Version VERSION_2_0_0_M1 = Version.parse("2.0.0.M1");
 
+	private static final List<String> VALID_VERSIONS = Arrays.asList("1.8", "9");
+
 	@Override
 	public void postProcessAfterResolution(ProjectRequest request, InitializrMetadata metadata) {
-		Version requestVersion = Version.safeParse(request.getBootVersion());
-		if (VERSION_2_0_0_M1.compareTo(requestVersion) <= 0) {
-			request.setJavaVersion("1.8");
+		if (!VALID_VERSIONS.contains(request.getJavaVersion())) {
+			Version requestVersion = Version.safeParse(request.getBootVersion());
+			if (VERSION_2_0_0_M1.compareTo(requestVersion) <= 0) {
+				request.setJavaVersion("1.8");
+			}
 		}
 	}
 
diff --git a/initializr-service/src/main/resources/application.yml b/initializr-service/src/main/resources/application.yml
index 458fedab..67238779 100644
--- a/initializr-service/src/main/resources/application.yml
+++ b/initializr-service/src/main/resources/application.yml
@@ -1251,11 +1251,13 @@ initializr:
       id: war
       default: false
   javaVersions:
+    - id: 9
+      default: false
     - id: 1.8
+      name: 8
       default: true
     - id: 1.7
-      default: false
-    - id: 1.6
+      name: 7
       default: false
   languages:
     - name: Java
diff --git a/initializr-service/src/test/java/io/spring/initializr/service/extension/Java9RequestPostProcessorTests.java b/initializr-service/src/test/java/io/spring/initializr/service/extension/Java9RequestPostProcessorTests.java
new file mode 100644
index 00000000..15b20fc7
--- /dev/null
+++ b/initializr-service/src/test/java/io/spring/initializr/service/extension/Java9RequestPostProcessorTests.java
@@ -0,0 +1,98 @@
+/*
+ * Copyright 2012-2017 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.spring.initializr.service.extension;
+
+import io.spring.initializr.generator.ProjectRequest;
+import org.junit.Test;
+
+/**
+ * Tests for {@link Java9RequestPostProcessor}.
+ *
+ * @author Stephane Nicoll
+ */
+public class Java9RequestPostProcessorTests
+		extends AbstractRequestPostProcessorTests {
+
+	@Test
+	public void java9CannotBeUsedWithSpringBoot1Maven() {
+		ProjectRequest request = createProjectRequest("web");
+		request.setBootVersion("1.5.8.RELEASE");
+		request.setJavaVersion("9");
+		generateMavenPom(request).hasJavaVersion("1.8");
+	}
+
+	@Test
+	public void java9CannotBeUsedWithSpringBoot1Gradle() {
+		ProjectRequest request = createProjectRequest("data-jpa");
+		request.setBootVersion("1.99.99.BUILD-SNAPSHOT");
+		request.setJavaVersion("9");
+		generateGradleBuild(request).hasJavaVersion("1.8");
+	}
+
+	@Test
+	public void java9CannotBeUsedWithGroovyMaven() {
+		ProjectRequest request = createProjectRequest("web");
+		request.setBootVersion("2.0.1.RELEASE");
+		request.setLanguage("groovy");
+		request.setJavaVersion("9");
+		generateMavenPom(request).hasJavaVersion("1.8");
+	}
+
+	@Test
+	public void java9CannotBeUsedWithKotlinMaven() {
+		ProjectRequest request = createProjectRequest("web");
+		request.setBootVersion("2.0.1.RELEASE");
+		request.setLanguage("kotlin");
+		request.setJavaVersion("9");
+		generateMavenPom(request).hasJavaVersion("1.8");
+	}
+
+	@Test
+	public void java9CannotBeUsedWithGroovyGradle() {
+		ProjectRequest request = createProjectRequest("data-jpa");
+		request.setBootVersion("2.0.1.RELEASE");
+		request.setLanguage("groovy");
+		request.setJavaVersion("9");
+		generateGradleBuild(request).hasJavaVersion("1.8");
+	}
+
+	@Test
+	public void java9CannotBeUsedWithKotlinGradle() {
+		ProjectRequest request = createProjectRequest("data-jpa");
+		request.setBootVersion("2.0.1.RELEASE");
+		request.setLanguage("kotlin");
+		request.setJavaVersion("9");
+		generateGradleBuild(request).hasJavaVersion("1.8");
+	}
+
+	@Test
+	public void java9CanBeUsedWithSpringBoot2Maven() {
+		ProjectRequest request = createProjectRequest("web");
+		request.setBootVersion("2.0.1.RELEASE");
+		request.setJavaVersion("9");
+		generateMavenPom(request).hasJavaVersion("9");
+	}
+
+	@Test
+	public void java9CanBeUsedWithSpringBoot2Gradle() {
+		ProjectRequest request = createProjectRequest("data-jpa");
+		request.setBootVersion("2.0.0.M3");
+		request.setJavaVersion("9");
+		generateGradleBuild(request).hasJavaVersion("9");
+	}
+
+}
diff --git a/initializr-service/src/test/java/io/spring/initializr/service/extension/SpringBoot2RequestPostProcessorTests.java b/initializr-service/src/test/java/io/spring/initializr/service/extension/SpringBoot2RequestPostProcessorTests.java
index 46dbe102..97dbc98d 100644
--- a/initializr-service/src/test/java/io/spring/initializr/service/extension/SpringBoot2RequestPostProcessorTests.java
+++ b/initializr-service/src/test/java/io/spring/initializr/service/extension/SpringBoot2RequestPostProcessorTests.java
@@ -43,4 +43,20 @@ public class SpringBoot2RequestPostProcessorTests
 		generateGradleBuild(request).hasJavaVersion("1.8");
 	}
 
+	@Test
+	public void java9CanBeUsedMaven() {
+		ProjectRequest request = createProjectRequest("web");
+		request.setBootVersion("2.0.0.BUILD-SNAPSHOT");
+		request.setJavaVersion("9");
+		generateMavenPom(request).hasJavaVersion("9");
+	}
+
+	@Test
+	public void java9CanBeUsedGradle() {
+		ProjectRequest request = createProjectRequest("data-jpa");
+		request.setBootVersion("2.0.0.M3");
+		request.setJavaVersion("9");
+		generateGradleBuild(request).hasJavaVersion("9");
+	}
+
 }