diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6205473..09d0a0c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,21 @@ 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).
 
+## [1.1.9] - 2025-12-22
+
+### Fixed
+
+- **CRITICAL:** Function redeclaration error for `wc_tpp_woocommerce_missing_notice()` affecting versions 1.1.3-1.1.8
+- Fatal error "Cannot redeclare function wc_tpp_woocommerce_missing_notice()" when plugin file loaded multiple times
+- Plugin activation and deactivation failures caused by function redeclaration
+
+### Technical Details
+
+- Wrapped `wc_tpp_woocommerce_missing_notice()` function in `function_exists()` check
+- Prevents fatal error during WordPress plugin activation/deactivation cycles
+- Ensures function can safely be declared even if file is included multiple times
+- Moved function declaration before WooCommerce check for better code organization
+
 ## [1.1.8] - 2025-12-22
 
 ### Fixed
diff --git a/composer.json b/composer.json
index 68eab5b..1c93b8e 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": "1.1.8",
+    "version": "1.1.9",
     "type": "wordpress-plugin",
     "license": "GPL-2.0-or-later",
     "authors": [
diff --git a/releases/wc-tier-and-package-prices-1.1.8.zip b/releases/wc-tier-and-package-prices-1.1.8.zip
new file mode 100644
index 0000000..3d8023a
Binary files /dev/null and b/releases/wc-tier-and-package-prices-1.1.8.zip differ
diff --git a/releases/wc-tier-and-package-prices-1.1.8.zip.md5 b/releases/wc-tier-and-package-prices-1.1.8.zip.md5
new file mode 100644
index 0000000..a48f098
--- /dev/null
+++ b/releases/wc-tier-and-package-prices-1.1.8.zip.md5
@@ -0,0 +1 @@
+666e1acad9f349982463b65d0e3e7fa3  wc-tier-and-package-prices-1.1.8.zip
diff --git a/releases/wc-tier-and-package-prices-1.1.8.zip.sha256 b/releases/wc-tier-and-package-prices-1.1.8.zip.sha256
new file mode 100644
index 0000000..fefe69f
--- /dev/null
+++ b/releases/wc-tier-and-package-prices-1.1.8.zip.sha256
@@ -0,0 +1 @@
+2c100d0d100a6fd7bd8f9c9b154d878a675bc795c5fddb19314bc9991b9a60ba  wc-tier-and-package-prices-1.1.8.zip
diff --git a/releases/wc-tier-and-package-prices-1.1.9.zip b/releases/wc-tier-and-package-prices-1.1.9.zip
new file mode 100644
index 0000000..9cd3e85
Binary files /dev/null and b/releases/wc-tier-and-package-prices-1.1.9.zip differ
diff --git a/releases/wc-tier-and-package-prices-1.1.9.zip.md5 b/releases/wc-tier-and-package-prices-1.1.9.zip.md5
new file mode 100644
index 0000000..d90747e
--- /dev/null
+++ b/releases/wc-tier-and-package-prices-1.1.9.zip.md5
@@ -0,0 +1 @@
+7421aceb8d1cc89b7d15b19d68cdfabe  wc-tier-and-package-prices-1.1.9.zip
diff --git a/releases/wc-tier-and-package-prices-1.1.9.zip.sha256 b/releases/wc-tier-and-package-prices-1.1.9.zip.sha256
new file mode 100644
index 0000000..a3a972e
--- /dev/null
+++ b/releases/wc-tier-and-package-prices-1.1.9.zip.sha256
@@ -0,0 +1 @@
+8224bf8b9bfc3dc760d77c61700d27c31db1a67b70834d8b6a4581df66fd45bd  wc-tier-and-package-prices-1.1.9.zip
diff --git a/wc-tier-and-package-prices.php b/wc-tier-and-package-prices.php
index a1824e4..fae1dd9 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: 1.1.8
+ * Version: 1.1.9
  * Author: Marco Graetsch
  * Author URI: https://src.bundespruefstelle.ch/magdev
  * Text Domain: wc-tier-package-prices
@@ -22,7 +22,7 @@ if (!defined('ABSPATH')) {
 }
 
 // Define plugin constants
-define('WC_TPP_VERSION', '1.1.8');
+define('WC_TPP_VERSION', '1.1.9');
 define('WC_TPP_PLUGIN_DIR', plugin_dir_path(__FILE__));
 define('WC_TPP_PLUGIN_URL', plugin_dir_url(__FILE__));
 define('WC_TPP_PLUGIN_BASENAME', plugin_basename(__FILE__));
@@ -30,6 +30,19 @@ define('WC_TPP_PLUGIN_BASENAME', plugin_basename(__FILE__));
 // Load Composer autoloader
 require_once WC_TPP_PLUGIN_DIR . 'vendor/autoload.php';
 
+/**
+ * Display WooCommerce missing notice
+ */
+if (!function_exists('wc_tpp_woocommerce_missing_notice')) {
+    function wc_tpp_woocommerce_missing_notice() {
+        ?>
+        <div class="notice notice-error">
+            <p><?php _e('WooCommerce Tier and Package Prices requires WooCommerce to be installed and active.', 'wc-tier-package-prices'); ?></p>
+        </div>
+        <?php
+    }
+}
+
 /**
  * Check if WooCommerce is active
  */
@@ -38,14 +51,6 @@ if (!in_array('woocommerce/woocommerce.php', apply_filters('active_plugins', get
     return;
 }
 
-function wc_tpp_woocommerce_missing_notice() {
-    ?>
-    <div class="notice notice-error">
-        <p><?php _e('WooCommerce Tier and Package Prices requires WooCommerce to be installed and active.', 'wc-tier-package-prices'); ?></p>
-    </div>
-    <?php
-}
-
 /**
  * Main plugin class
  */