diff --git a/redback-authentication/redback-authentication-api/src/main/java/org/apache/archiva/redback/authentication/AuthenticationConstants.java b/redback-authentication/redback-authentication-api/src/main/java/org/apache/archiva/redback/authentication/AuthenticationConstants.java
index 88e4d2b6..143b5fb9 100644
--- a/redback-authentication/redback-authentication-api/src/main/java/org/apache/archiva/redback/authentication/AuthenticationConstants.java
+++ b/redback-authentication/redback-authentication-api/src/main/java/org/apache/archiva/redback/authentication/AuthenticationConstants.java
@@ -34,4 +34,14 @@ public class AuthenticationConstants
      */
     public static final String AUTHN_RUNTIME_EXCEPTION = "2";
 
+    /**
+     * @since 2.1
+     */
+    public static final String AUTHN_LOCKED_USER_EXCEPTION = "3";
+
+    /**
+     * @since 2.1
+     */
+    public static final String AUTHN_MUST_CHANGE_PASSWORD_EXCEPTION = "4";
+
 }