diff --git a/src/effectivejava/chapter12/item90/Period.java b/src/effectivejava/chapter12/item90/Period.java
index 71aaf712..07df3731 100644
--- a/src/effectivejava/chapter12/item90/Period.java
+++ b/src/effectivejava/chapter12/item90/Period.java
@@ -43,6 +43,10 @@ private static class SerializationProxy implements Serializable {
 
         private static final long serialVersionUID =
                 234098243823485285L; // Any number will do (Item 87)
+
+        private Object readResolve() {
+            return new Period(start, end); // Uses public constructor
+        }
     }
 
     // writeReplace method for the serialization proxy pattern