Index: src/main/java/java/beans/PropertyDescriptor.java =================================================================== --- src/main/java/java/beans/PropertyDescriptor.java (revision 453254) +++ src/main/java/java/beans/PropertyDescriptor.java (working copy) @@ -180,7 +180,7 @@ @Override public boolean equals(Object object) { - boolean result = (object != null); + boolean result = (object != null && object instanceof PropertyDescriptor); if (result) { PropertyDescriptor pd = (PropertyDescriptor) object;