diff --git a/action/migration.php b/action/migration.php
index 99c4ed1..74944fd 100644
--- a/action/migration.php
+++ b/action/migration.php
@@ -4,7 +4,7 @@
 
 class action_plugin_structpublish_migration extends DokuWiki_Action_Plugin
 {
-    const MIN_DB_STRUCT = 19;
+    public const MIN_DB_STRUCT = 19;
 
     /** @var string  */
     protected $table = 'data_structpublish';
diff --git a/meta/Constants.php b/meta/Constants.php
index 30ca7a5..e2c3979 100644
--- a/meta/Constants.php
+++ b/meta/Constants.php
@@ -10,13 +10,13 @@
 class Constants
 {
     // a page can be in one current status
-    const STATUS_DRAFT = 'draft';
-    const STATUS_APPROVED = 'approved';
-    const STATUS_PUBLISHED = 'published';
+    public const STATUS_DRAFT = 'draft';
+    public const STATUS_APPROVED = 'approved';
+    public const STATUS_PUBLISHED = 'published';
 
     // an action transitions a page from one status to another
-    const ACTION_APPROVE = 'approve';
-    const ACTION_PUBLISH = 'publish';
+    public const ACTION_APPROVE = 'approve';
+    public const ACTION_PUBLISH = 'publish';
 
     /**
      * Convenience function mapping transition actions to resulting status