diff --git a/src/interfaces/jdbc/org/postgresql/util/PSQLState.java b/src/interfaces/jdbc/org/postgresql/util/PSQLState.java
index 152170e0c97..b1d1efa63e3 100644
--- a/src/interfaces/jdbc/org/postgresql/util/PSQLState.java
+++ b/src/interfaces/jdbc/org/postgresql/util/PSQLState.java
@@ -10,7 +10,7 @@
  
  package org.postgresql.util;
  
- public class PSQLState
+ public class PSQLState implements java.io.Serializable
  {
  	private String state;