Java 8 forEach cannot be resolved to a variable

I wanted to learn the differences between Java 8 and Java 7. At the moment I am looking into the Java 8 forEach loop.

public class Main {
    public static void main(String[] args){
        List<String> strings = Arrays.asList("hello","my","name","is","test");
        strings.stream().forEach(s -> System.out.println(s));
    }
}

This code is generating the following error for me:

Exception in thread "main" java.lang.Error: Unresolved compilation problems: 
s cannot be resolved to a variable
Syntax error on token "-", -- expected
s cannot be resolved to a variable

at Main.main(Main.java:7)

I am sure that the JDK aswell as the JRE are Java 8, since the compuler can recognize the forEach method from the List but not the -> parameter.