IntelliJ ignores maven.compiler.target property

Hello,

I am testing a bit and wanted to use Java 8 instead of 5, so I added the maven.compiler.target and maven.compiler.source properties to the pom.xml:

<properties>
    <maven.compiler.target>1.8</maven.compiler.target>
    <maven.compiler.source>1.8</maven.compiler.source>
</properties>

But for some reason it still fails. When I try to use IntStream it fails with an message that it is available since 1.8.

It works when I set the maven-compiler-plugin with the versions:

<build>
    <plugins>
        <plugin>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.5.1</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>
    </plugins>
</build>

According to https://maven.apache.org/plugins/maven-compiler-plugin/examples/set-compiler-source-and-target.html this should work.

Why is that so?

Thanks.