$ cat package-info.java
/*
 * Copyright (c) 
 */

/**
 * This package contains javadoc.
 */
@ParametersAreNonnullByDefault
package example;

import javax.annotation.ParametersAreNonnullByDefault;

$ cat TestConfig.xml
<?xml version="1.0"?>
<!DOCTYPE module PUBLIC
          "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
          "https://checkstyle.org/dtds/configuration_1_3.dtd">

<module name="Checker">
    <property name="charset" value="UTF-8"/>

    <module name="TreeWalker">
<module name="MissingJavadocPackage" />
    </module>
</module>

$ java -jar checkstyle-8.25-all.jar -c TestConfig.xml package-info.java
Starting audit...
[ERROR] /<redacted>/src/main/java/example/package-info.java:9: Missing javadoc for package-info.java file.
Audit done.