Java APIs

I have the following iterator implementation:

public abstract class SomeCollection<T> {
  protected ArrayList<T> items = new ArrayList<T>();
  public Iterator<T> iterator() {
    return new Iterator<T>() {
      int currentItem = -1;
      public boolean hasNext() { ... }
      public T next() { return items.get(++currentItem);}
      public void remove() { ... }
    };
  }
}

However, when I try to use the iterator in the following method:

    for (someType item : someCollection) {
      ...
    }

I get the error for incompatible types, where java.lang.Object is found when someType is required.

Any idea, anyone?