diff --git a/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/embedded/tomcat/TomcatReactiveWebServerFactoryTests.java b/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/embedded/tomcat/TomcatReactiveWebServerFactoryTests.java
index 9db30a7d21..516ca60452 100644
--- a/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/embedded/tomcat/TomcatReactiveWebServerFactoryTests.java
+++ b/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/embedded/tomcat/TomcatReactiveWebServerFactoryTests.java
@@ -251,7 +251,7 @@ class TomcatReactiveWebServerFactoryTests extends AbstractReactiveWebServerFacto
 		assertThat(((PortInUseException) ex).getPort()).isEqualTo(blockedPort);
 	}
 
-	public interface BlockedPortAction {
+	private interface BlockedPortAction {
 
 		void run(int port);