diff --git a/Controller.php b/Controller.php
index a23b359..c2223df 100644
--- a/Controller.php
+++ b/Controller.php
@@ -45,7 +45,7 @@ class Controller extends ModuleAbstract implements WebInterface
      * @var string
      * @since 1.0.0
      */
-    const MODULE_PATH = __DIR__;
+    /* public */ const MODULE_PATH = __DIR__;
 
     /**
      * Module version.
@@ -53,7 +53,7 @@ class Controller extends ModuleAbstract implements WebInterface
      * @var string
      * @since 1.0.0
      */
-    const MODULE_VERSION = '1.0.0';
+    /* public */ const MODULE_VERSION = '1.0.0';
 
     /**
      * Module name.
@@ -61,7 +61,7 @@ class Controller extends ModuleAbstract implements WebInterface
      * @var string
      * @since 1.0.0
      */
-    const MODULE_NAME = 'Sales';
+    /* public */ const MODULE_NAME = 'Sales';
 
     /**
      * Providing.
diff --git a/Models/InvoiceStatus.php b/Models/InvoiceStatus.php
index 4df34b0..c336bbf 100644
--- a/Models/InvoiceStatus.php
+++ b/Models/InvoiceStatus.php
@@ -30,15 +30,15 @@ use phpOMS\Datatypes\Enum;
  */
 abstract class InvoiceStatus extends Enum
 {
-    const BLOCKED        = 0; /* Invoice needs approval */
-    const DRAFT          = 1; /* Invoice is still in draft */
-    const READY          = 2; /* Invoice is ready for accounting transfer */
-    const UNPAID         = 3; /* Invoice is not paid */
-    const PAID_PARTIALLY = 4; /* Invoice is partially paid */
-    const PAID           = 5; /* Invoice is paid */
-    const OFFSETTING     = 6; /* This invoice may receive a credit */
-    const OPEN           = 7; /* offer & confirmation */
-    const CHANGED        = 8; /* offer & confirmation */
-    const CLOSED         = 9; /* offer & confirmation */
-    const ACCEPTED       = 10; /* offer & confirmation */
+    /* public */ const BLOCKED        = 0; /* Invoice needs approval */
+    /* public */ const DRAFT          = 1; /* Invoice is still in draft */
+    /* public */ const READY          = 2; /* Invoice is ready for accounting transfer */
+    /* public */ const UNPAID         = 3; /* Invoice is not paid */
+    /* public */ const PAID_PARTIALLY = 4; /* Invoice is partially paid */
+    /* public */ const PAID           = 5; /* Invoice is paid */
+    /* public */ const OFFSETTING     = 6; /* This invoice may receive a credit */
+    /* public */ const OPEN           = 7; /* offer & confirmation */
+    /* public */ const CHANGED        = 8; /* offer & confirmation */
+    /* public */ const CLOSED         = 9; /* offer & confirmation */
+    /* public */ const ACCEPTED       = 10; /* offer & confirmation */
 }
diff --git a/Models/InvoiceType.php b/Models/InvoiceType.php
index e5e517b..267cec3 100644
--- a/Models/InvoiceType.php
+++ b/Models/InvoiceType.php
@@ -30,11 +30,11 @@ use phpOMS\Datatypes\Enum;
  */
 abstract class InvoiceType extends Enum
 {
-    const OFFER = 0;
+    /* public */ const OFFER = 0;
 
-    const CONTRACT_NOTE = 1;
+    /* public */ const CONTRACT_NOTE = 1;
 
-    const DELIVERY_NOTE = 2;
+    /* public */ const DELIVERY_NOTE = 2;
 
-    const BILL = 3;
+    /* public */ const BILL = 3;
 }