diff --git a/spring-boot/src/test/java/org/springframework/boot/context/embedded/AbstractEmbeddedServletContainerFactoryTests.java b/spring-boot/src/test/java/org/springframework/boot/context/embedded/AbstractEmbeddedServletContainerFactoryTests.java
index 47d6ed1f666..7fc2b120d34 100644
--- a/spring-boot/src/test/java/org/springframework/boot/context/embedded/AbstractEmbeddedServletContainerFactoryTests.java
+++ b/spring-boot/src/test/java/org/springframework/boot/context/embedded/AbstractEmbeddedServletContainerFactoryTests.java
@@ -680,7 +680,7 @@ public abstract class AbstractEmbeddedServletContainerFactoryTests {
 	@Test
 	public void rootServletContextResource() throws Exception {
 		AbstractEmbeddedServletContainerFactory factory = getFactory();
-		AtomicReference<URL> rootResource = new AtomicReference<URL>();
+		final AtomicReference<URL> rootResource = new AtomicReference<URL>();
 		this.container = factory
 				.getEmbeddedServletContainer(new ServletContextInitializer() {
 					@Override