@KeyFor refinement doesn't work for autoboxed types

Environment: Checker Framework 1.9.11, Oracle JDK 1.8.0_65, Windows 7/8.1

Example:

import java.util.Map;

public abstract class KeyForRefinement {
    public void working1(Object key) {
        Map<Object, Object> m = getObjectMap();
        if (!m.containsKey(key)) {
            m.put(key, new Object());
        }
        m.get(key).toString();
    }

    public void working2(Integer key) {
        Map<Integer, Object> m = getIntegerMap();
        if (!m.containsKey(key)) {
            m.put(key, new Object());
        }
        m.get(key).toString();
    }

    public void working3(Double key) {
        Map<Double, Object> m = getDoubleMap();
        if (!m.containsKey(key)) {
            m.put(key, new Object());
        }
        m.get(key).toString();
    }

    public void notWorking1(int key) {
        Map<Integer, Object> m = getIntegerMap();
        if (!m.containsKey(key)) {
            m.put(key, new Object());
        }
        m.get(key).toString();  // Should not generate error but does
    }

    public void notWorking2(double key) {
        Map<Double, Object> m = getDoubleMap();
        if (!m.containsKey(key)) {
            m.put(key, new Object());
        }
        m.get(key).toString();  // Should not generate error but does
    }

    public abstract Map<Object, Object> getObjectMap();
    public abstract Map<Integer, Object> getIntegerMap();
    public abstract Map<Double, Object> getDoubleMap();
}

When Map#get is invoked with an object argument, the key variable is correctly refined to be of the @KeyFor type. However, invoking the same method with a primitive type does not appear to perform the same refinement.