enhanced for loop (for each) for java.util.collection - Type mismatch: cannot convert from element type Object to String

i had the following code that i wanted to convert to the new enhanced for loop:
private String myMethod(Collection c){
    for(Iterator<String> it = c.iterator(); it.hasNext();){
        String s = it.next();
        ...
    }
}




so i rewrote it like this:
private String myMethod(Collection c){
    for(String s : c){
        ...
    }
}
but that code gave me the following "error" in eclipse:
Type mismatch: cannot convert from element type Object to String



here's the final, error-free solution:
private String myMethod(Collection<String> c){
    for(String s : c){
        ...
    }
}