diff --git a/CHANGELOG.md b/CHANGELOG.md
index c35e69f..cb9cc8b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,27 @@ All notable changes to WooCommerce Tier and Package Prices will be documented in
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.1.13] - 2025-12-22
+
+### Fixed
+
+- **CRITICAL:** Class redeclaration errors for all plugin component classes affecting version 1.1.12
+- Fatal errors "Cannot redeclare class WC_TPP_Admin", "Cannot redeclare class WC_TPP_Product_Meta", "Cannot redeclare class WC_TPP_Frontend", "Cannot redeclare class WC_TPP_Cart", "Cannot redeclare class WC_TPP_Settings"
+- Plugin functionality completely broken in v1.1.12 - no settings page, no frontend display, no backend controls
+- All plugin features now working correctly after adding class guards
+
+### Technical Details
+
+- Wrapped all 5 plugin component class declarations in `class_exists()` checks:
+  - `WC_TPP_Admin` (includes/class-wc-tpp-admin.php)
+  - `WC_TPP_Product_Meta` (includes/class-wc-tpp-product-meta.php)
+  - `WC_TPP_Frontend` (includes/class-wc-tpp-frontend.php)
+  - `WC_TPP_Cart` (includes/class-wc-tpp-cart.php)
+  - `WC_TPP_Settings` (includes/class-wc-tpp-settings.php)
+- Completes comprehensive redeclaration protection started in v1.1.9-1.1.12
+- All functions, constants, and classes now fully protected against redeclaration
+- Plugin now activates and functions correctly without fatal errors
+
 ## [1.1.12] - 2025-12-22
 
 ### Fixed
diff --git a/composer.json b/composer.json
index d2c4d7a..f7976dd 100644
--- a/composer.json
+++ b/composer.json
@@ -1,7 +1,7 @@
 {
     "name": "magdev/wc-tier-package-prices",
     "description": "WooCommerce plugin for tier pricing and package prices with Twig templates",
-    "version": "1.1.12",
+    "version": "1.1.13",
     "type": "wordpress-plugin",
     "license": "GPL-2.0-or-later",
     "authors": [
diff --git a/includes/class-wc-tpp-admin.php b/includes/class-wc-tpp-admin.php
index 9b2d70c..16b6fc0 100644
--- a/includes/class-wc-tpp-admin.php
+++ b/includes/class-wc-tpp-admin.php
@@ -7,7 +7,8 @@ if (!defined('ABSPATH')) {
     exit;
 }
 
-class WC_TPP_Admin {
+if (!class_exists('WC_TPP_Admin')) {
+    class WC_TPP_Admin {
 
     public function __construct() {
         add_filter('woocommerce_get_settings_pages', array($this, 'add_settings_page'));
@@ -29,3 +30,4 @@ class WC_TPP_Admin {
         }
     }
 }
+}
diff --git a/includes/class-wc-tpp-cart.php b/includes/class-wc-tpp-cart.php
index 50fa6f0..8f9f576 100644
--- a/includes/class-wc-tpp-cart.php
+++ b/includes/class-wc-tpp-cart.php
@@ -7,7 +7,8 @@ if (!defined('ABSPATH')) {
     exit;
 }
 
-class WC_TPP_Cart {
+if (!class_exists('WC_TPP_Cart')) {
+    class WC_TPP_Cart {
 
     public function __construct() {
         add_action('woocommerce_before_calculate_totals', array($this, 'apply_tier_package_pricing'), 10, 1);
@@ -247,3 +248,4 @@ class WC_TPP_Cart {
         return $editable;
     }
 }
+}
diff --git a/includes/class-wc-tpp-frontend.php b/includes/class-wc-tpp-frontend.php
index b488dfc..35ab309 100644
--- a/includes/class-wc-tpp-frontend.php
+++ b/includes/class-wc-tpp-frontend.php
@@ -7,7 +7,8 @@ if (!defined('ABSPATH')) {
     exit;
 }
 
-class WC_TPP_Frontend {
+if (!class_exists('WC_TPP_Frontend')) {
+    class WC_TPP_Frontend {
 
     public function __construct() {
         add_action('wp_enqueue_scripts', array($this, 'enqueue_scripts'));
@@ -182,3 +183,4 @@ class WC_TPP_Frontend {
         return $new_html;
     }
 }
+}
diff --git a/includes/class-wc-tpp-product-meta.php b/includes/class-wc-tpp-product-meta.php
index 3137afb..4f6f780 100644
--- a/includes/class-wc-tpp-product-meta.php
+++ b/includes/class-wc-tpp-product-meta.php
@@ -7,7 +7,8 @@ if (!defined('ABSPATH')) {
     exit;
 }
 
-class WC_TPP_Product_Meta {
+if (!class_exists('WC_TPP_Product_Meta')) {
+    class WC_TPP_Product_Meta {
 
     public function __construct() {
         add_action('woocommerce_product_options_pricing', array($this, 'add_tier_pricing_fields'));
@@ -167,3 +168,4 @@ class WC_TPP_Product_Meta {
         update_post_meta($post_id, '_wc_tpp_restrict_to_packages', $restrict_to_packages);
     }
 }
+}
diff --git a/includes/class-wc-tpp-settings.php b/includes/class-wc-tpp-settings.php
index a8b10ab..dfd1938 100644
--- a/includes/class-wc-tpp-settings.php
+++ b/includes/class-wc-tpp-settings.php
@@ -18,7 +18,8 @@ if (!class_exists('WC_Settings_Page')) {
 /**
  * WC_TPP_Settings class
  */
-class WC_TPP_Settings extends WC_Settings_Page {
+if (!class_exists('WC_TPP_Settings')) {
+    class WC_TPP_Settings extends WC_Settings_Page {
 
     /**
      * Constructor
@@ -139,5 +140,9 @@ class WC_TPP_Settings extends WC_Settings_Page {
         WC_Admin_Settings::save_fields($settings);
     }
 }
+}
 
-return new WC_TPP_Settings();
+if (class_exists('WC_TPP_Settings')) {
+    return new WC_TPP_Settings();
+}
+return null;
diff --git a/releases/wc-tier-and-package-prices-1.1.13.zip b/releases/wc-tier-and-package-prices-1.1.13.zip
new file mode 100644
index 0000000..00bfd97
Binary files /dev/null and b/releases/wc-tier-and-package-prices-1.1.13.zip differ
diff --git a/releases/wc-tier-and-package-prices-1.1.13.zip.md5 b/releases/wc-tier-and-package-prices-1.1.13.zip.md5
new file mode 100644
index 0000000..514ce03
--- /dev/null
+++ b/releases/wc-tier-and-package-prices-1.1.13.zip.md5
@@ -0,0 +1 @@
+8572eed399554905fbf331d18f0677a0  wc-tier-and-package-prices-1.1.13.zip
diff --git a/releases/wc-tier-and-package-prices-1.1.13.zip.sha256 b/releases/wc-tier-and-package-prices-1.1.13.zip.sha256
new file mode 100644
index 0000000..6aa5383
--- /dev/null
+++ b/releases/wc-tier-and-package-prices-1.1.13.zip.sha256
@@ -0,0 +1 @@
+83e29b2e40dd43e77bd83cd03d4ccc54ef53555b55544eba4d38161101f79f20  wc-tier-and-package-prices-1.1.13.zip
diff --git a/wc-tier-and-package-prices.php b/wc-tier-and-package-prices.php
index 2eaf14e..27ae403 100644
--- a/wc-tier-and-package-prices.php
+++ b/wc-tier-and-package-prices.php
@@ -4,7 +4,7 @@
  * Plugin Name: WooCommerce Tier and Package Prices
  * Plugin URI: https://src.bundespruefstelle.ch/magdev/wc-tier-package-prices
  * Description: Add tier pricing and package prices to WooCommerce products with configurable quantities at fixed prices
- * Version: 1.1.12
+ * Version: 1.1.13
  * Author: Marco Graetsch
  * Author URI: https://src.bundespruefstelle.ch/magdev
  * Text Domain: wc-tier-package-prices
@@ -23,7 +23,7 @@ if (!defined('ABSPATH')) {
 
 // Define plugin constants
 if (!defined('WC_TPP_VERSION')) {
-    define('WC_TPP_VERSION', '1.1.12');
+    define('WC_TPP_VERSION', '1.1.13');
 }
 if (!defined('WC_TPP_PLUGIN_DIR')) {
     define('WC_TPP_PLUGIN_DIR', plugin_dir_path(__FILE__));