diff --git a/src/Exceptions/ShortcodeDeregisterException.php b/src/Exceptions/ShortcodeDeregisterException.php
index f93b9d0..11259b4 100644
--- a/src/Exceptions/ShortcodeDeregisterException.php
+++ b/src/Exceptions/ShortcodeDeregisterException.php
@@ -7,5 +7,8 @@
  */
 class ShortcodeDeregisterException extends ShortcodeException
 {
+    /**
+     * @const string
+     */
     const MISSING = 'The shortcode \'%s\' does not exist in the current library';
 }
\ No newline at end of file
diff --git a/src/Exceptions/ShortcodeRegisterException.php b/src/Exceptions/ShortcodeRegisterException.php
index d357437..9baf7d6 100644
--- a/src/Exceptions/ShortcodeRegisterException.php
+++ b/src/Exceptions/ShortcodeRegisterException.php
@@ -7,6 +7,13 @@
  */
 class ShortcodeRegisterException extends ShortcodeException
 {
+    /**
+     * @const string
+     */
     const DUPLICATE = 'The shortcode \'%s\' has already been registered';
+
+    /**
+     * @const string
+     */
     const MISSING = 'No shortcode with identifier \'%s\' has been registered';
 }
\ No newline at end of file