diff --git a/.github/workflows/code-quality.yml b/.github/workflows/code-quality.yml
index ced0ea1..d2844f5 100644
--- a/.github/workflows/code-quality.yml
+++ b/.github/workflows/code-quality.yml
@@ -39,7 +39,7 @@ jobs:
         run: npm run build
 
   phpcs:
-    name: PHPCS
+    name: PHPCS and PHPStan
     runs-on: ubuntu-latest
 
     steps:
@@ -69,3 +69,6 @@ jobs:
 
       - name: Run PHPCS
         run: composer phpcs
+
+      - name: Run PHPStan
+        run: vendor/bin/phpstan analyse --error-format=github --memory-limit=1G
diff --git a/composer.json b/composer.json
index 3256ee2..4b8892d 100644
--- a/composer.json
+++ b/composer.json
@@ -12,8 +12,12 @@
     "prefer-stable": true,
     "require-dev": {
         "dealerdirect/phpcodesniffer-composer-installer": "^1.0",
+        "php-stubs/woocommerce-stubs": "^3.0",
+        "php-stubs/wordpress-stubs": "^6.0",
         "phpcompatibility/phpcompatibility-wp": "^2.1",
+        "phpstan/phpstan": "^2.0",
         "squizlabs/php_codesniffer": "^3.7",
+        "szepeviktor/phpstan-wordpress": "^2.0",
         "wp-coding-standards/wpcs": "^3.0"
     },
     "config": {
@@ -30,6 +34,10 @@
     "scripts": {
         "phpcs": "vendor/bin/phpcs",
         "phpcbf": "vendor/bin/phpcbf",
-        "lint": "@phpcs"
+        "phpstan": "php -d memory_limit=1G vendor/bin/phpstan analyse --memory-limit=1G",
+        "lint": [
+            "@phpcs",
+            "@phpstan"
+        ]
     }
 }
diff --git a/composer.lock b/composer.lock
index f50f407..f2920c0 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "38ca719cf177f1b476473798eccdc613",
+    "content-hash": "d4e246de27646b0d637e8ff3982d2952",
     "packages": [],
     "packages-dev": [
         {
@@ -103,6 +103,112 @@
             ],
             "time": "2026-05-06T08:26:05+00:00"
         },
+        {
+            "name": "php-stubs/woocommerce-stubs",
+            "version": "v3.8.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/php-stubs/woocommerce-stubs.git",
+                "reference": "74583d44d4510c431dd548190bfdbd7592aab57e"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/php-stubs/woocommerce-stubs/zipball/74583d44d4510c431dd548190bfdbd7592aab57e",
+                "reference": "74583d44d4510c431dd548190bfdbd7592aab57e",
+                "shasum": ""
+            },
+            "require-dev": {
+                "ext-gettext": "*",
+                "ext-hash": "*",
+                "ext-json": "*",
+                "ext-mbstring": "*",
+                "ext-openssl": "*",
+                "giacocorsiglia/stubs-generator": "^0.5.0",
+                "php": "~7.1",
+                "woocommerce/woocommerce": "3.8.0"
+            },
+            "suggest": {
+                "symfony/polyfill-php73": "Symfony polyfill backporting some PHP 7.3+ features to lower PHP versions",
+                "szepeviktor/phpstan-wordpress": "WordPress extensions for PHPStan"
+            },
+            "type": "library",
+            "extra": {
+                "installer-paths": {
+                    "{$name}/": [
+                        "type:wordpress-plugin"
+                    ]
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "description": "WooCommerce function and class declaration stubs for static analysis.",
+            "homepage": "https://github.com/php-stubs/woocommerce-stubs",
+            "keywords": [
+                "PHPStan",
+                "static analysis",
+                "woocommerce",
+                "wordpress"
+            ],
+            "support": {
+                "issues": "https://github.com/php-stubs/woocommerce-stubs/issues",
+                "source": "https://github.com/php-stubs/woocommerce-stubs/tree/v3.8.0"
+            },
+            "time": "2019-11-21T22:17:45+00:00"
+        },
+        {
+            "name": "php-stubs/wordpress-stubs",
+            "version": "v6.9.4",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/php-stubs/wordpress-stubs.git",
+                "reference": "90a9412826b9944f93b10bf41d795b5fe68abcd5"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/php-stubs/wordpress-stubs/zipball/90a9412826b9944f93b10bf41d795b5fe68abcd5",
+                "reference": "90a9412826b9944f93b10bf41d795b5fe68abcd5",
+                "shasum": ""
+            },
+            "conflict": {
+                "phpdocumentor/reflection-docblock": "5.6.1"
+            },
+            "require-dev": {
+                "dealerdirect/phpcodesniffer-composer-installer": "^1.0",
+                "nikic/php-parser": "^5.5",
+                "php": "^7.4 || ^8.0",
+                "php-stubs/generator": "^0.8.6",
+                "phpdocumentor/reflection-docblock": "^6.0",
+                "phpstan/phpstan": "^2.1",
+                "phpunit/phpunit": "^9.5",
+                "symfony/polyfill-php80": "*",
+                "szepeviktor/phpcs-psr-12-neutron-hybrid-ruleset": "^1.1.1",
+                "wp-coding-standards/wpcs": "3.1.0 as 2.3.0"
+            },
+            "suggest": {
+                "paragonie/sodium_compat": "Pure PHP implementation of libsodium",
+                "symfony/polyfill-php80": "Symfony polyfill backporting some PHP 8.0+ features to lower PHP versions",
+                "szepeviktor/phpstan-wordpress": "WordPress extensions for PHPStan"
+            },
+            "type": "library",
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "description": "WordPress function and class declaration stubs for static analysis.",
+            "homepage": "https://github.com/php-stubs/wordpress-stubs",
+            "keywords": [
+                "PHPStan",
+                "static analysis",
+                "wordpress"
+            ],
+            "support": {
+                "issues": "https://github.com/php-stubs/wordpress-stubs/issues",
+                "source": "https://github.com/php-stubs/wordpress-stubs/tree/v6.9.4"
+            },
+            "time": "2026-05-01T20:36:01+00:00"
+        },
         {
             "name": "phpcompatibility/php-compatibility",
             "version": "9.3.5",
@@ -491,6 +597,70 @@
             ],
             "time": "2026-07-27T10:28:41+00:00"
         },
+        {
+            "name": "phpstan/phpstan",
+            "version": "2.2.14",
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/phpstan/phpstan/zipball/9c672e7a8e791dfc3d30e55f683e73fc0b63a3ac",
+                "reference": "9c672e7a8e791dfc3d30e55f683e73fc0b63a3ac",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^7.4|^8.0"
+            },
+            "conflict": {
+                "phpstan/phpstan-shim": "*"
+            },
+            "bin": [
+                "phpstan",
+                "phpstan.phar"
+            ],
+            "type": "library",
+            "autoload": {
+                "files": [
+                    "bootstrap.php"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Ondřej Mirtes"
+                },
+                {
+                    "name": "Markus Staab"
+                },
+                {
+                    "name": "Vincent Langlet"
+                }
+            ],
+            "description": "PHPStan - PHP Static Analysis Tool",
+            "keywords": [
+                "dev",
+                "static analysis"
+            ],
+            "support": {
+                "docs": "https://phpstan.org/user-guide/getting-started",
+                "forum": "https://github.com/phpstan/phpstan/discussions",
+                "issues": "https://github.com/phpstan/phpstan/issues",
+                "security": "https://github.com/phpstan/phpstan/security/policy",
+                "source": "https://github.com/phpstan/phpstan-src"
+            },
+            "funding": [
+                {
+                    "url": "https://github.com/ondrejmirtes",
+                    "type": "github"
+                },
+                {
+                    "url": "https://github.com/phpstan",
+                    "type": "github"
+                }
+            ],
+            "time": "2026-09-12T21:39:33+00:00"
+        },
         {
             "name": "squizlabs/php_codesniffer",
             "version": "3.13.6",
@@ -570,6 +740,69 @@
             ],
             "time": "2026-08-06T00:17:32+00:00"
         },
+        {
+            "name": "szepeviktor/phpstan-wordpress",
+            "version": "v2.0.4",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/szepeviktor/phpstan-wordpress.git",
+                "reference": "84577e2ea1e4c2a95537fe5ea2ac8e18f4ceab1a"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/szepeviktor/phpstan-wordpress/zipball/84577e2ea1e4c2a95537fe5ea2ac8e18f4ceab1a",
+                "reference": "84577e2ea1e4c2a95537fe5ea2ac8e18f4ceab1a",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^7.4 || ^8.0",
+                "php-stubs/wordpress-stubs": ">=6.6.2",
+                "phpstan/phpstan": "^2.0"
+            },
+            "require-dev": {
+                "composer/composer": "^2.1.14",
+                "composer/semver": "^3.4",
+                "dealerdirect/phpcodesniffer-composer-installer": "^1.0",
+                "php-parallel-lint/php-parallel-lint": "^1.1",
+                "phpstan/phpstan-strict-rules": "^2.0",
+                "phpunit/phpunit": "^9.0",
+                "szepeviktor/phpcs-psr-12-neutron-hybrid-ruleset": "^1.0",
+                "wp-coding-standards/wpcs": "3.1.0 as 2.3.0"
+            },
+            "suggest": {
+                "swissspidy/phpstan-no-private": "Detect usage of internal core functions, classes and methods"
+            },
+            "type": "phpstan-extension",
+            "extra": {
+                "phpstan": {
+                    "includes": [
+                        "extension.neon"
+                    ]
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "SzepeViktor\\PHPStan\\WordPress\\": "src/"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "description": "WordPress extensions for PHPStan",
+            "keywords": [
+                "PHPStan",
+                "code analyse",
+                "code analysis",
+                "static analysis",
+                "wordpress"
+            ],
+            "support": {
+                "issues": "https://github.com/szepeviktor/phpstan-wordpress/issues",
+                "source": "https://github.com/szepeviktor/phpstan-wordpress/tree/v2.0.4"
+            },
+            "time": "2026-05-22T16:22:09+00:00"
+        },
         {
             "name": "wp-coding-standards/wpcs",
             "version": "3.4.1",
diff --git a/includes/Admin/Admin_Settings.php b/includes/Admin/Admin_Settings.php
index 22c0661..55509ed 100644
--- a/includes/Admin/Admin_Settings.php
+++ b/includes/Admin/Admin_Settings.php
@@ -24,7 +24,7 @@ class Admin_Settings {
 	public function __construct() {
 		// For the admin interface.
 		add_action( 'admin_menu', array( $this, 'register_settings_menu' ) );
-		add_action( 'plugin_action_links_' . Functions::get_plugin_path(), array( $this, 'plugin_settings_link' ) );
+		add_filter( 'plugin_action_links_' . Functions::get_plugin_path(), array( $this, 'plugin_settings_link' ) );
 
 		// init tabs here.
 		new Tabs\Settings();
@@ -93,7 +93,7 @@ public static function get_settings_tabs() {
 			$tabs       = apply_filters( 'sce_admin_tabs', $tabs );
 			$tab_html   = '<nav class="nav-tab-wrapper">';
 			$tabs_count = count( $tabs );
-			if ( $tabs && ! empty( $tabs ) && is_array( $tabs ) ) {
+			if ( is_array( $tabs ) && count( $tabs ) > 0 ) {
 				$active_tab = Functions::get_admin_tab();
 				if ( null === $active_tab ) {
 					$active_tab = 'settings';
@@ -148,9 +148,9 @@ public static function get_settings_tabs() {
 				 *
 				 * @since 5.1.0
 				 *
-				 * @param array Associative array of tabs.
-				 * @param string Tab
-				 * @param string Sub Tab
+				 * @param array  $sub_tabs       Associative array of tabs.
+				 * @param string $current_tab    Current tab.
+				 * @param string $current_sub_tab Current sub-tab.
 				 */
 				$sub_tabs = apply_filters( 'sce_admin_sub_tabs', array(), $current_tab, $current_sub_tab );
 
@@ -158,7 +158,7 @@ public static function get_settings_tabs() {
 				if ( null === $current_tab && null === $current_sub_tab ) {
 					$current_tab = 'settings';
 				}
-				if ( $sub_tabs && ! empty( $sub_tabs ) && is_array( $sub_tabs ) ) {
+				if ( is_array( $sub_tabs ) && count( $sub_tabs ) > 0 ) {
 					if ( null === $current_sub_tab ) {
 						$current_sub_tab = '';
 					}
@@ -202,9 +202,7 @@ public static function get_settings_tabs() {
 							$sub_tab_html_array[] = sprintf( '<a href="%s" class="%s" id="mpp-tab-%s">%s</a>', esc_url( $tab_url ), esc_attr( implode( ' ', $classes ) ), esc_attr( $tab_get ), esc_html( $sub_tab['label'] ) );
 						}
 					}
-					if ( ! empty( $sub_tab_html_array ) ) {
-						echo '<nav class="mpp-sub-links">' . wp_kses_post( rtrim( implode( ' | ', $sub_tab_html_array ), ' | ' ) ) . '</nav>';
-					}
+					echo '<nav class="mpp-sub-links">' . wp_kses_post( rtrim( implode( ' | ', $sub_tab_html_array ), ' | ' ) ) . '</nav>';
 					if ( $do_subtab_action ) {
 						/**
 						 * Perform a sub tab action.
@@ -214,7 +212,6 @@ public static function get_settings_tabs() {
 						 * @since 5.1.0
 						 *
 						 * mpp_admin_sub_tab_{current_tab}_{current_sub_tab}
-						 * @param string Sub Tab
 						 */
 						do_action(
 							sprintf( // phpcs:ignore
@@ -234,9 +231,8 @@ public static function get_settings_tabs() {
 					 *
 					 * @since 5.1.0
 					 *
-					 * @param string $action Can be any action.
-					 * @param string Tab
-					 * @param string Sub Tab
+					 * @param string $current_tab     Current tab.
+					 * @param string $current_sub_tab Current sub-tab.
 					 */
 					do_action( $do_action, $current_tab, $current_sub_tab );
 				}
diff --git a/includes/Admin/Tabs/Integrations.php b/includes/Admin/Tabs/Integrations.php
index 90f119a..7eb18af 100644
--- a/includes/Admin/Tabs/Integrations.php
+++ b/includes/Admin/Tabs/Integrations.php
@@ -29,7 +29,7 @@ class Integrations extends Tabs {
 	/**
 	 * Tab to run actions against.
 	 *
-	 * @var $tab Settings tab.
+	 * @var string Settings tab.
 	 */
 	protected $tab = 'integrations';
 
@@ -39,7 +39,7 @@ class Integrations extends Tabs {
 	public function __construct() {
 		add_filter( 'sce_admin_tabs', array( $this, 'add_tab' ), 1, 1 );
 		add_filter( 'sce_admin_sub_tabs', array( $this, 'add_sub_tab' ), 1, 3 );
-		add_action( 'sce_output_' . $this->tab, array( $this, 'output_settings' ), 1, 3 );
+		add_action( 'sce_output_' . $this->tab, array( $this, 'output_settings' ), 1, 2 );
 
 		/**
 		 * Mailchimp admin panel actions.
diff --git a/includes/Admin/Tabs/Settings.php b/includes/Admin/Tabs/Settings.php
index 5a72cc5..3090cce 100644
--- a/includes/Admin/Tabs/Settings.php
+++ b/includes/Admin/Tabs/Settings.php
@@ -22,7 +22,7 @@ class Settings extends Tabs {
 	/**
 	 * Tab to run actions against.
 	 *
-	 * @var $tab Settings tab.
+	 * @var string Settings tab.
 	 */
 	private $tab = 'settings';
 
@@ -32,7 +32,7 @@ class Settings extends Tabs {
 	public function __construct() {
 		add_filter( 'sce_admin_tabs', array( $this, 'add_tab' ), 1, 1 );
 		add_filter( 'sce_admin_sub_tabs', array( $this, 'add_sub_tab' ), 1, 3 );
-		add_action( 'sce_output_' . sanitize_key( $this->tab ), array( $this, 'output_settings' ), 1, 3 );
+		add_action( 'sce_output_' . sanitize_key( $this->tab ), array( $this, 'output_settings' ), 1, 2 );
 	}
 
 	/**
diff --git a/includes/Admin/Tabs/Support.php b/includes/Admin/Tabs/Support.php
index ad83eab..164e0c3 100644
--- a/includes/Admin/Tabs/Support.php
+++ b/includes/Admin/Tabs/Support.php
@@ -22,7 +22,7 @@ class Support extends Tabs {
 	/**
 	 * Tab to run actions against.
 	 *
-	 * @var $tab Settings tab.
+	 * @var string Settings tab.
 	 */
 	protected $tab = 'support';
 
@@ -32,7 +32,7 @@ class Support extends Tabs {
 	public function __construct() {
 		add_filter( 'sce_admin_tabs', array( $this, 'add_tab' ), 1, 1 );
 		add_filter( 'sce_admin_sub_tabs', array( $this, 'add_sub_tab' ), 1, 3 );
-		add_action( 'sce_output_' . $this->tab, array( $this, 'output_settings' ), 1, 3 );
+		add_action( 'sce_output_' . $this->tab, array( $this, 'output_settings' ), 1, 2 );
 	}
 
 	/**
diff --git a/includes/Admin/Tabs/Tabs.php b/includes/Admin/Tabs/Tabs.php
index 5502f7a..e7f2ca4 100644
--- a/includes/Admin/Tabs/Tabs.php
+++ b/includes/Admin/Tabs/Tabs.php
@@ -19,7 +19,7 @@ abstract class Tabs {
 	/**
 	 * Tab to run actions against.
 	 *
-	 * @var $tab Current tab.
+	 * @var string Current tab.
 	 */
 	private $tab;
 
diff --git a/includes/Ajax.php b/includes/Ajax.php
index c1d5df3..8a5768c 100644
--- a/includes/Ajax.php
+++ b/includes/Ajax.php
@@ -58,8 +58,8 @@ public static function ajax_get_time_left() {
 		 *
 		 * @since 2.3.6
 		 *
-		 * @param bool Whether to allow unlimited comment editing
-		 * @param object Comment object
+		 * @param bool             $unlimited Whether to allow unlimited comment editing.
+		 * @param \WP_Comment|null $comment   Comment object.
 		 */
 		$sce_unlimited_editing = apply_filters( 'sce_unlimited_editing', false, $comment );
 		if ( $sce_unlimited_editing ) {
@@ -84,10 +84,10 @@ public static function ajax_get_time_left() {
 		 *
 		 * @since 2.8.0
 		 *
-		 * @param int    Current comment editing time.
-		 * @param string Current time format in date/time format.
-		 * @param int    Current Post ID.
-		 * @param int    Current Comment ID.
+		 * @param int    $time_left    Current comment editing time.
+		 * @param string $comment_time Current time format in date/time format.
+		 * @param int    $post_id      Current post ID.
+		 * @param int    $comment_id   Current comment ID.
 		 */
 		$time_left = apply_filters( 'sce_get_comment_time_left', $comment_time_result['comment_time'], $comment_time, $post_id, $comment_id );
 
@@ -271,7 +271,7 @@ public static function ajax_save_comment() {
 			add_filter( 'pre_option_comment_moderation', array( static::class, 'short_circuit_comment_moderation' ) );
 			add_filter( 'pre_option_comment_whitelist', array( static::class, 'short_circuit_comment_moderation' ) );
 			add_filter( 'option_comment_moderation', '__return_false' ); // Needed to bypass moderation.
-			remove_filter( 'comment_text', array( Simple_Comment_Editing::get_instance(), 'add_edit_interface' ), 1000, 2 ); // Prevents adding in any SCE links to the comment.
+			remove_filter( 'comment_text', array( Simple_Comment_Editing::get_instance(), 'add_edit_interface' ), 1000 ); // Prevents adding in any SCE links to the comment.
 			if ( check_comment( $comment_to_save['comment_author'], $comment_to_save['comment_author_email'], $comment_to_save['comment_author_url'], $new_comment_content, $comment_to_save['comment_author_IP'], $comment_to_save['comment_agent'], $comment_to_save['comment_type'] ) ) {
 				$comment_to_save['comment_approved'] = 1;
 			} else {
@@ -355,7 +355,7 @@ public static function ajax_save_comment() {
 		 *
 		 * Allow third parties to disable Akismet.
 		 *
-		 * @param bool true if Akismet is enabled
+		 * @param bool $enabled True if Akismet is enabled.
 		 */
 		$akismet_enabled = apply_filters( 'sce_akismet_enabled', true );
 
@@ -418,7 +418,7 @@ public static function ajax_save_comment() {
 	 *
 	 * @param bool|mixed $option_value The option value for moderation.
 	 *
-	 * @return int Return a string so there is not a boolean value.
+	 * @return string Return a string so there is not a boolean value.
 	 */
 	public static function short_circuit_comment_moderation( $option_value ) {
 		return 'approved';
diff --git a/includes/Functions.php b/includes/Functions.php
index b4d225a..5e13a82 100644
--- a/includes/Functions.php
+++ b/includes/Functions.php
@@ -26,7 +26,7 @@ class Functions {
 	/**
 	 * Checks if the plugin is on a multisite install.
 	 *
-	 * @return true if multisite, false if not.
+	 * @return bool True if multisite, false if not.
 	 */
 	public static function is_multisite() {
 		if ( ! function_exists( 'is_plugin_active_for_network' ) ) {
@@ -48,7 +48,7 @@ public static function get_comment_time() {
 			return self::$comment_time;
 		}
 
-		$time_do_edit = Options::get_options( false, 'timer' );
+		$time_do_edit = absint( Options::get_options( false, 'timer' ) );
 		/**
 		* Filter: sce_comment_time
 		*
@@ -71,7 +71,7 @@ public static function get_comment_time() {
 	 * @access private
 	 * @since 1.5.0
 	 *
-	 * @param WP_Comment $comment Comment Object.
+	 * @param \WP_Comment $comment Comment Object.
 	 * @return string Comment text
 	 */
 	public static function get_comment_content( $comment ) {
@@ -105,8 +105,8 @@ public static function can_edit( $comment_id, $post_id ) {
 		 *
 		 * @since 2.9.1
 		 *
-		 * @param bool  true If user can edit the comment
-		 * @param WP_Comment $comment Comment object user has left (may be unset)
+		 * @param bool       $can_edit If the user can edit the comment.
+		 * @param \WP_Comment $comment Comment object user has left (may be unset)
 		 * @param WP_Post    $post    Post object (may be unset)
 		 */
 		$can_edit_pre = apply_filters( 'sce_can_edit_pre', true, $comment, $post );
@@ -148,11 +148,11 @@ public static function can_edit( $comment_id, $post_id ) {
 		 *
 		 * @since 2.2.0
 		 *
-		 * @param boolean            Whether to bypass cookie authentication
-		 * @param object $comment    Comment object
-		 * @param int    $comment_id The comment ID
-		 * @param int    $post_id    The post ID of the comment
-		 * @param int    $user_id    The logged in user ID
+		 * @param bool       $bypass     Whether to bypass cookie authentication.
+		 * @param \WP_Comment $comment    Comment object.
+		 * @param int        $comment_id The comment ID.
+		 * @param int        $post_id    The post ID of the comment.
+		 * @param int        $user_id    The logged in user ID.
 		 */
 		$cookie_bypass = apply_filters( 'sce_can_edit_cookie_bypass', $cookie_bypass, $comment, $comment_id, $post_id, $user_id );
 
@@ -184,10 +184,10 @@ public static function can_edit( $comment_id, $post_id ) {
 		 *
 		 * @since 1.3.2
 		 *
-		 * @param bool  true If user can edit the comment
-		 * @param object $comment Comment object user has left
-		 * @param int $comment_id Comment ID of the comment
-		 * @param int $post_id Post ID of the comment
+		 * @param bool       $can_edit   If the user can edit the comment.
+		 * @param \WP_Comment $comment    Comment object user has left.
+		 * @param int        $comment_id Comment ID of the comment.
+		 * @param int        $post_id    Post ID of the comment.
 		 */
 		return apply_filters( 'sce_can_edit', true, $comment, $comment_id, $post_id );
 	} //end can_edit
@@ -201,7 +201,7 @@ public static function can_edit( $comment_id, $post_id ) {
 	 * @since 1.5.0
 	 *
 	 * @param string $name Cookie name.
-	 * @return string $value Cookie value
+	 * @return string|false Cookie value, or false when absent.
 	 */
 	public static function get_cookie_value( $name ) {
 		if ( isset( $_COOKIE[ $name ] ) ) {
@@ -265,8 +265,8 @@ public static function sanitize_attribute( $attributes, $attribute, $type = 'tex
 	/**
 	 * Convert Hex to RGBA
 	 *
-	 * @param string $color   The color to convert.
-	 * @param int    $opacity The opacity.
+	 * @param string    $color   The color to convert.
+	 * @param int|false $opacity The opacity.
 	 *
 	 * @return string rgba attribute.
 	 */
@@ -388,7 +388,7 @@ public static function get_plugin_file() {
 	/**
 	 * Return the version for the plugin.
 	 *
-	 * @return float version for the plugin.
+	 * @return string Version for the plugin.
 	 */
 	public static function get_plugin_version() {
 		return SCE_VERSION;
@@ -405,7 +405,7 @@ public static function get_plugin_logo() {
 		 *
 		 * @since 3.0.0
 		 *
-		 * @param string URL to the plugin logo.
+		 * @param string $url URL to the plugin logo.
 		 */
 		return apply_filters( 'sce_plugin_logo_full', self::get_plugin_url( '/images/logo.png' ) );
 	}
@@ -421,7 +421,7 @@ public static function get_plugin_author() {
 		 *
 		 * @since 3.0.0
 		 *
-		 * @param string Plugin Author name.
+		 * @param string $author Plugin author name.
 		 */
 		$plugin_author = apply_filters( 'sce_plugin_author', 'Ronald Huereca' );
 		return $plugin_author;
@@ -438,7 +438,7 @@ public static function get_plugin_author_uri() {
 		 *
 		 * @since 3.0.0
 		 *
-		 * @param string Plugin Author URI.
+		 * @param string $author_uri Plugin author URI.
 		 */
 		$plugin_author = apply_filters( 'sce_plugin_author_uri', 'https://github.com/ronalfy/simple-comment-editing' );
 		return $plugin_author;
@@ -455,7 +455,7 @@ public static function get_plugin_icon() {
 		 *
 		 * @since 3.0.0
 		 *
-		 * @param string URL to the plugin icon.
+		 * @param string $icon_url URL to the plugin icon.
 		 */
 		return apply_filters( 'sce_plugin_icon', self::get_plugin_url( '/images/logo.png' ) );
 	}
@@ -473,7 +473,7 @@ public static function get_plugin_name() {
 		 *
 		 * @since 3.0.0
 		 *
-		 * @param string Plugin name.
+		 * @param string $name Plugin name.
 		 */
 		return apply_filters( 'sce_plugin_name', __( 'Simple Comment Editing', 'simple-comment-editing' ) );
 	}
@@ -491,7 +491,7 @@ public static function get_plugin_description() {
 		 *
 		 * @since 3.0.0
 		 *
-		 * @param string Plugin description.
+		 * @param string $description Plugin description.
 		 */
 		return apply_filters( 'sce_plugin_description', __( 'Allow your users to edit comments.', 'simple-comment-editing' ) );
 	}
@@ -507,7 +507,7 @@ public static function get_plugin_uri() {
 		 *
 		 * @since 3.0.0
 		 *
-		 * @param string Plugin URI.
+		 * @param string $uri Plugin URI.
 		 */
 		return apply_filters( 'sce_plugin_uri', 'https://github.com/ronalfy/simple-comment-editing' );
 	}
@@ -523,7 +523,7 @@ public static function get_plugin_menu_name() {
 		 *
 		 * @since 3.0.0
 		 *
-		 * @param string Plugin Menu Name.
+		 * @param string $menu_name Plugin menu name.
 		 */
 		return apply_filters( 'sce_plugin_menu_name', __( 'Simple Comment Editing', 'simple-comment-editing' ) );
 	}
@@ -539,7 +539,7 @@ public static function get_plugin_title() {
 		 *
 		 * @since 3.0.0
 		 *
-		 * @param string Plugin Menu Name.
+		 * @param string $title Plugin menu title.
 		 */
 		return apply_filters( 'sce_plugin_menu_title', self::get_plugin_name() );
 	}
diff --git a/includes/Mailchimp.php b/includes/Mailchimp.php
index 6f5b878..a6fb374 100644
--- a/includes/Mailchimp.php
+++ b/includes/Mailchimp.php
@@ -81,9 +81,9 @@ public static function comment_posted_mailchimp( $comment_id, $maybe_comment_app
 	/**
 	 * Add a subscriber to mailchimp.
 	 *
-	 * @param int        $comment_id The comment ID.
-	 * @param string     $email      The email address.
-	 * @param WP_Comment $comment    The comment object.
+	 * @param int         $comment_id The comment ID.
+	 * @param string      $email      The email address.
+	 * @param \WP_Comment $comment    The comment object.
 	 *
 	 * @return bool True if the subscriber was added, false otherwise.
 	 */
diff --git a/includes/WooCommerce.php b/includes/WooCommerce.php
index 781f9cd..f7cbe3d 100644
--- a/includes/WooCommerce.php
+++ b/includes/WooCommerce.php
@@ -32,10 +32,10 @@ public static function run() {
 	/**
 	 * Add the WooCommerce rating field.
 	 *
-	 * @param array      $return Return data.
-	 * @param WP_Comment $comment Comment.
-	 * @param int        $post_id Post ID.
-	 * @param int        $comment_id Comment ID.
+	 * @param array       $return Return data.
+	 * @param \WP_Comment $comment Comment.
+	 * @param int         $post_id Post ID.
+	 * @param int         $comment_id Comment ID.
 	 *
 	 * @return array
 	 */
@@ -59,10 +59,10 @@ public static function return_woocommerce_rating_fields( $return, $comment, $pos
 	/**
 	 * Save the WooCommerce rating field.
 	 *
-	 * @param WP_Comment $comment_to_save Comment to save.
-	 * @param int        $post_id Post ID.
-	 * @param int        $comment_id Comment ID.
-	 * @param WP_Comment $original_comment Original comment.
+	 * @param array       $comment_to_save Comment to save.
+	 * @param int         $post_id Post ID.
+	 * @param int         $comment_id Comment ID.
+	 * @param \WP_Comment $original_comment Original comment.
 	 */
 	public static function save_woocommerce_rating_fields( $comment_to_save, $post_id, $comment_id, $original_comment ) {
 		if ( 'review' !== $comment_to_save['comment_type'] ) {
@@ -95,10 +95,10 @@ public static function save_woocommerce_rating_fields( $comment_to_save, $post_i
 	/**
 	 * Add WooCommerce fields to the comment form.
 	 *
-	 * @param string     $markup HTML markup to return.
-	 * @param int        $post_id Post ID.
-	 * @param int        $comment_id Comment ID.
-	 * @param WP_Comment $comment WP_Comment object.
+	 * @param string      $markup HTML markup to return.
+	 * @param int         $post_id Post ID.
+	 * @param int         $comment_id Comment ID.
+	 * @param \WP_Comment $comment WP_Comment object.
 	 *
 	 * @return string HTML markup.
 	 */
diff --git a/phpcs.xml.dist b/phpcs.xml.dist
index b2e9598..fe41dd6 100644
--- a/phpcs.xml.dist
+++ b/phpcs.xml.dist
@@ -7,6 +7,7 @@
 	<exclude-pattern>*/dist/*</exclude-pattern>
 	<exclude-pattern>*/lib/*</exclude-pattern>
 	<exclude-pattern>*/node_modules/*</exclude-pattern>
+	<exclude-pattern>*/phpstan-stubs.php</exclude-pattern>
 	<exclude-pattern>*/vendor/*</exclude-pattern>
 
 	<arg name="extensions" value="php" />
diff --git a/phpstan-stubs.php b/phpstan-stubs.php
new file mode 100644
index 0000000..7e1e2b6
--- /dev/null
+++ b/phpstan-stubs.php
@@ -0,0 +1,22 @@
+<?php
+
+const SCE_SLUG = '';
+const COOKIEPATH = '';
+
+/**
+ * Akismet functions loaded only when the optional plugin is active.
+ *
+ * @param mixed $key API key.
+ *
+ * @return string
+ */
+function akismet_verify_key( $key ) {}
+
+/**
+ * Check a stored comment with Akismet.
+ *
+ * @param int $comment_id Comment ID.
+ *
+ * @return string
+ */
+function akismet_check_db_comment( $comment_id ) {}
diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 0000000..0d0a3d7
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,16 @@
+includes:
+	- vendor/szepeviktor/phpstan-wordpress/extension.neon
+
+parameters:
+	level: 3
+	paths:
+		- includes
+		- index.php
+		- simple-comment-editing.php
+		- uninstall.php
+	bootstrapFiles:
+		- vendor/autoload.php
+	scanFiles:
+		- vendor/php-stubs/woocommerce-stubs/woocommerce-stubs.php
+		- phpstan-stubs.php
+	treatPhpDocTypesAsCertain: false
diff --git a/simple-comment-editing.php b/simple-comment-editing.php
index 4f5bda9..6ab6b29 100644
--- a/simple-comment-editing.php
+++ b/simple-comment-editing.php
@@ -42,7 +42,7 @@ class Simple_Comment_Editing {
 	/**
 	 * Error object for WP_Error.
 	 *
-	 * @var WP_Error Error object for WP_Error.
+	 * @var \WP_Error Error object for WP_Error.
 	 */
 	public static $errors;
 
@@ -176,8 +176,8 @@ public function init() {
 	 *
 	 * Called via the comment_text or comment_excerpt filter to add the SCE editing interface to a comment.
 	 *
-	 * @param string $comment_content The comment content.
-	 * @param array  $passed_comment  The comment object.
+	 * @param string      $comment_content The comment content.
+	 * @param array|false $passed_comment The comment object.
 	 *
 	 * @since 1.0
 	 */
@@ -222,7 +222,7 @@ public function add_edit_interface( $comment_content, $passed_comment = false )
 		 *
 		 * @since 2.3.0
 		 *
-		 * @param array Array of classes for the initial wrapper
+		 * @param array $classes Array of classes for the initial wrapper.
 		 */
 		$classes = apply_filters( 'sce_wrapper_class', $classes );
 
@@ -249,7 +249,7 @@ public function add_edit_interface( $comment_content, $passed_comment = false )
 		*
 		* @since 2.0.0
 		*
-		* @param string Translated click to edit text
+		* @param string $text Translated click-to-edit text.
 		*/
 		$click_to_edit_text = apply_filters( 'sce_text_edit', __( 'Click to Edit', 'simple-comment-editing' ) );
 
@@ -260,7 +260,7 @@ public function add_edit_interface( $comment_content, $passed_comment = false )
 		*
 		* @since 2.6.0
 		*
-		* @param string Translated delete text
+		* @param string $text Translated delete text.
 		*/
 		$delete_edit_text = apply_filters( 'sce_text_edit_delete', __( 'Delete Comment', 'simple-comment-editing' ) );
 
@@ -286,9 +286,11 @@ public function add_edit_interface( $comment_content, $passed_comment = false )
 		 *
 		 * @since 2.3.0
 		 *
-		 * @param bool Whether to show the timer or not
+		 * @param bool $show_timer Whether to show the timer.
 		 */
-		if ( apply_filters( 'sce_show_timer', true ) && false === apply_filters( 'sce_unlimited_editing', false, $comment ) ) {
+		$show_timer        = apply_filters( 'sce_show_timer', true );
+		$unlimited_editing = apply_filters( 'sce_unlimited_editing', false, $comment );
+		if ( $show_timer && false === $unlimited_editing ) {
 			$sce_content .= '<span class="sce-seperator">&nbsp;&ndash;&nbsp;</span>';
 			$sce_content .= '<span class="sce-timer"></span>';
 		}
@@ -309,10 +311,10 @@ public function add_edit_interface( $comment_content, $passed_comment = false )
 		*
 		* @since 3.0.0
 		*
-		* @param string Empty string
-		* @param int post_id POST ID
-		* @param int comment_id Comment ID
-		* @param WP_Comment comment Comment object.
+		* @param string     $content    Empty string.
+		* @param int        $post_id    Post ID.
+		* @param int        $comment_id Comment ID.
+		* @param \WP_Comment $comment    Comment object.
 		*/
 		$textarea_content .= apply_filters( 'sce_extra_fields_pre', '', $post_id, $comment_id, $comment );
 		$textarea_content .= '<div class="sce-comment-textarea">';
@@ -326,9 +328,9 @@ public function add_edit_interface( $comment_content, $passed_comment = false )
 		*
 		* @since 1.5.0
 		*
-		* @param string Empty string
-		* @param int post_id POST ID
-		* @param int comment_id Comment ID
+		* @param string $content    Empty string.
+		* @param int    $post_id    Post ID.
+		* @param int    $comment_id Comment ID.
 		*/
 		$textarea_content .= apply_filters( 'sce_extra_fields', '', $post_id, $comment_id );
 
@@ -342,7 +344,7 @@ public function add_edit_interface( $comment_content, $passed_comment = false )
 		*
 		* @since 2.0.0
 		*
-		* @param string Translated save text
+		* @param string $text Translated save text.
 		*/
 		$save_text = apply_filters( 'sce_text_save', __( 'Save', 'simple-comment-editing' ) );
 
@@ -353,7 +355,7 @@ public function add_edit_interface( $comment_content, $passed_comment = false )
 		*
 		* @since 2.0.0
 		*
-		* @param string Translated cancel text
+		* @param string $text Translated cancel text.
 		*/
 		$cancel_text = apply_filters( 'sce_text_cancel', __( 'Cancel', 'simple-comment-editing' ) );
 
@@ -364,7 +366,7 @@ public function add_edit_interface( $comment_content, $passed_comment = false )
 		*
 		* @since 2.0.0
 		*
-		* @param string Translated delete text
+		* @param string $text Translated delete text.
 		*/
 		$delete_text = apply_filters( 'sce_text_delete', __( 'Delete', 'simple-comment-editing' ) );
 
@@ -375,7 +377,7 @@ public function add_edit_interface( $comment_content, $passed_comment = false )
 		 *
 		 * Add an extra item before the save button text. This is useful for adding icons.
 		 *
-		 * @param string Empty string
+		 * @param string $content Empty string.
 		 */
 		$textarea_buttons .= sprintf( '<button class="sce-comment-save">%s%s</button>', apply_filters( 'sce_button_extra_save', '' ), esc_html( $save_text ) );
 
@@ -384,7 +386,7 @@ public function add_edit_interface( $comment_content, $passed_comment = false )
 		 *
 		 * Add an extra item before the cancel button text. This is useful for adding icons.
 		 *
-		 * @param string Empty string
+		 * @param string $content Empty string.
 		 */
 		$textarea_buttons .= sprintf( '<button class="sce-comment-cancel">%s%s</button>', apply_filters( 'sce_button_extra_cancel', '' ), esc_html( $cancel_text ) );
 
@@ -393,7 +395,7 @@ public function add_edit_interface( $comment_content, $passed_comment = false )
 		 *
 		 * Add an extra item before the delete button text. This is useful for adding icons.
 		 *
-		 * @param string Empty string
+		 * @param string $content Empty string.
 		 */
 		$textarea_buttons .= self::$allow_delete ? sprintf( '<button class="sce-comment-delete">%s%s</button>', apply_filters( 'sce_button_extra_delete', '' ), esc_html( $delete_text ) ) : '';
 		$textarea_buttons .= '</div><!-- .sce-comment-edit-buttons-group -->';
@@ -403,7 +405,7 @@ public function add_edit_interface( $comment_content, $passed_comment = false )
 		 *
 		 * Filter allow you to hide the timer
 		 *
-		 * @param bool Whether to show the timer or not
+		 * @param bool $show_timer Whether to show the timer.
 		 */
 		if ( apply_filters( 'sce_show_timer', true ) ) {
 			$textarea_buttons .= '<div class="sce-timer"></div>';
@@ -634,7 +636,7 @@ public function add_scripts() {
 		 *
 		 * @since 1.5.0
 		 *
-		 * @param bool  true to load scripts, false not
+		 * @param bool $load_scripts Whether to load scripts.
 		 */
 		$load_scripts = apply_filters( 'sce_load_scripts', false );
 		if ( ! $load_scripts ) {
@@ -676,7 +678,7 @@ public function add_scripts() {
 		 *
 		 * @since 2.1.7
 		 *
-		 * @param bool true to show a confirmation, false if not
+		 * @param bool $allow_confirmation Whether to show a confirmation.
 		 */
 		$allow_delete_confirmation = (bool) apply_filters( 'sce_allow_delete_confirmation', true );
 
@@ -737,11 +739,11 @@ public function comment_posted( $comment_id ) {
 		 * Filter: sce_can_edit_cookie_bypass
 		 * Bypass the cookie based user verification.
 		 *
-		 * @param boolean            Whether to bypass cookie authentication
-		 * @param object $comment    Comment object
-		 * @param int    $comment_id The comment ID
-		 * @param int    $post_id    The post ID of the comment
-		 * @param int    $user_id    The logged in user ID
+		 * @param bool             $bypass     Whether to bypass cookie authentication.
+		 * @param \WP_Comment|null $comment    Comment object.
+		 * @param int        $comment_id The comment ID.
+		 * @param int|string $post_id    The post ID of the comment.
+		 * @param int        $user_id    The logged in user ID.
 		 *
 		 * @return boolean
 		 */
@@ -768,7 +770,7 @@ public function comment_posted( $comment_id ) {
 	 * @since 1.5.0
 	 *
 	 * @param string $name Cookie name.
-	 * @return string $value Cookie value.
+	 * @return string|false Cookie value, or false when absent.
 	 */
 	private function get_cookie_value( $name ) {
 		if ( isset( $_COOKIE[ $name ] ) ) {
@@ -787,7 +789,7 @@ private function get_cookie_value( $name ) {
 	 * @since 1.5.0
 	 *
 	 * @param int $comment_id Comment ID.
-	 * @return obj Comment Object
+	 * @return \WP_Comment|null Comment object.
 	 */
 	public static function get_comment( $comment_id ) {
 		if ( isset( $GLOBALS['comment'] ) ) {
@@ -809,7 +811,7 @@ public static function get_comment( $comment_id ) {
 	 * @param int    $post_id Post ID.
 	 * @param int    $comment_id Comment ID.
 	 * @param string $return_action 'ajax', 'setcookie, 'removecookie'.
-	 * @return JSON Array of cookie data only returned during Ajax requests
+	 * @return void
 	 */
 	public function generate_cookie_data( $post_id = 0, $comment_id = 0, $return_action = 'ajax' ) {
 		if ( 'ajax' === $return_action ) {
@@ -838,7 +840,7 @@ public function generate_cookie_data( $post_id = 0, $comment_id = 0, $return_act
 		 *
 		 * @since 2.7.1
 		 *
-		 * @param bool  true to use the comment IP filter.
+		 * @param bool $use_ip Whether to use the comment IP filter.
 		 */
 		if ( apply_filters( 'sce_pre_comment_user_ip', true ) ) {
 			// Props: https://github.com/timreeves.
@@ -911,8 +913,8 @@ public function maybe_load_scripts( $yes ) {
 			return true;
 		}
 
-		if ( ! isset( $_COOKIE ) || empty( $_COOKIE ) ) {
-			return;
+		if ( empty( $_COOKIE ) ) {
+			return false;
 		}
 		$has_cookie = false;
 		foreach ( $_COOKIE as $cookie_name => $cookie_value ) {
@@ -931,7 +933,7 @@ public function maybe_load_scripts( $yes ) {
 	 *
 	 * @since 1.0
 	 *
-	 * @param associative array $comment The results from get_comment( $id, ARRAY_A ).
+	 * @param array $comment The results from get_comment( $id, ARRAY_A ).
 	 */
 	public static function remove_comment_cookie( $comment ) {
 		if ( ! is_array( $comment ) ) {