diff --git a/phpstan.neon b/phpstan.neon
index aa9effb6625..bd86e81a28c 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -16,3 +16,4 @@ parameters:
     ignoreErrors:
         - '#Class Event constructor invoked with 1 parameter, 4-5 required\.#'
         - '#Constant [A-Z_]+ not found\.#'
+        - '#might not be defined\.#'
diff --git a/upload/admin/controller/extension/advertise/google.php b/upload/admin/controller/extension/advertise/google.php
index ef85a803e7a..1d10ee9620f 100644
--- a/upload/admin/controller/extension/advertise/google.php
+++ b/upload/admin/controller/extension/advertise/google.php
@@ -268,7 +268,7 @@ public function advertise() {
 
                 if (!empty($select)) {
                     $this->model_extension_advertise_google->setAdvertisingBySelect($select, $target_ids, $this->store_id);
-                } else if (!empty($filter_data)) {
+                } else {
                     $this->model_extension_advertise_google->setAdvertisingByFilter($filter_data, $target_ids, $this->store_id);
                 }
 
diff --git a/upload/admin/controller/extension/module/pilibaba_button.php b/upload/admin/controller/extension/module/pilibaba_button.php
index 1948588814b..d0a9028c409 100644
--- a/upload/admin/controller/extension/module/pilibaba_button.php
+++ b/upload/admin/controller/extension/module/pilibaba_button.php
@@ -1,5 +1,7 @@
 <?php
 class ControllerExtensionModulePilibabaButton extends Controller {
+	private $error = array();
+
 	public function index() {
 		$this->load->language('extension/module/pilibaba_button');
 
diff --git a/upload/admin/controller/extension/module/pp_braintree_button.php b/upload/admin/controller/extension/module/pp_braintree_button.php
index bce800a753d..b010ae4cf10 100644
--- a/upload/admin/controller/extension/module/pp_braintree_button.php
+++ b/upload/admin/controller/extension/module/pp_braintree_button.php
@@ -1,5 +1,7 @@
 <?php
 class ControllerExtensionModulePPBraintreeButton extends Controller {
+	private $error = array();
+
 	public function index() {
 		$this->load->language('extension/module/pp_braintree_button');
 
diff --git a/upload/admin/controller/extension/payment/klarna_invoice.php b/upload/admin/controller/extension/payment/klarna_invoice.php
index 584d9cd84a1..405927ec125 100644
--- a/upload/admin/controller/extension/payment/klarna_invoice.php
+++ b/upload/admin/controller/extension/payment/klarna_invoice.php
@@ -1,6 +1,7 @@
 <?php
 class ControllerExtensionPaymentKlarnaInvoice extends Controller {
 	private $error = array();
+	private $pclasses = array();
 
 	public function index() {
 		$this->load->language('extension/payment/klarna_invoice');
diff --git a/upload/admin/controller/extension/payment/securetrading_pp.php b/upload/admin/controller/extension/payment/securetrading_pp.php
index c333116d06c..e2895f795d6 100644
--- a/upload/admin/controller/extension/payment/securetrading_pp.php
+++ b/upload/admin/controller/extension/payment/securetrading_pp.php
@@ -337,7 +337,7 @@ public function release() {
 
 		$amount = number_format($this->request->post['amount'], 2);
 
-		if (isset($this->request->post['order_id']) && $this->request->post['order_id'] != '' && isset($amount) && $amount > 0) {
+		if (isset($this->request->post['order_id']) && $this->request->post['order_id'] != '' && $amount > 0) {
 			$this->load->model('extension/payment/securetrading_pp');
 
 			$securetrading_pp_order = $this->model_extension_payment_securetrading_pp->getOrder($this->request->post['order_id']);
diff --git a/upload/admin/controller/extension/payment/securetrading_ws.php b/upload/admin/controller/extension/payment/securetrading_ws.php
index 1d8698a7acc..c0c9cd21c67 100644
--- a/upload/admin/controller/extension/payment/securetrading_ws.php
+++ b/upload/admin/controller/extension/payment/securetrading_ws.php
@@ -411,7 +411,7 @@ public function release() {
 
 		$amount = number_format($this->request->post['amount'], 2);
 
-		if (isset($this->request->post['order_id']) && $this->request->post['order_id'] != '' && isset($amount) && $amount > 0) {
+		if (isset($this->request->post['order_id']) && $this->request->post['order_id'] != '' && $amount > 0) {
 			$this->load->model('extension/payment/securetrading_ws');
 
 			$securetrading_ws_order = $this->model_extension_payment_securetrading_ws->getOrder($this->request->post['order_id']);
diff --git a/upload/admin/controller/extension/report/customer_activity.php b/upload/admin/controller/extension/report/customer_activity.php
index 270e48a92c7..c2d753a608f 100644
--- a/upload/admin/controller/extension/report/customer_activity.php
+++ b/upload/admin/controller/extension/report/customer_activity.php
@@ -1,5 +1,7 @@
 <?php
 class ControllerExtensionReportCustomerActivity extends Controller {
+	private $error = array();
+
 	public function index() {
 		$this->load->language('extension/report/customer_activity');
 
diff --git a/upload/admin/controller/extension/report/customer_order.php b/upload/admin/controller/extension/report/customer_order.php
index 4751e3c5062..707f04d315c 100644
--- a/upload/admin/controller/extension/report/customer_order.php
+++ b/upload/admin/controller/extension/report/customer_order.php
@@ -1,5 +1,7 @@
 <?php
 class ControllerExtensionReportCustomerOrder extends Controller {
+	private $error = array();
+
 	public function index() {
 		$this->load->language('extension/report/customer_order');
 
diff --git a/upload/admin/controller/extension/report/customer_reward.php b/upload/admin/controller/extension/report/customer_reward.php
index fdf9985269f..ccbdd32e31e 100644
--- a/upload/admin/controller/extension/report/customer_reward.php
+++ b/upload/admin/controller/extension/report/customer_reward.php
@@ -1,5 +1,7 @@
 <?php
 class ControllerExtensionReportCustomerReward extends Controller {
+	private $error = array();
+
 	public function index() {
 		$this->load->language('extension/report/customer_reward');
 
diff --git a/upload/admin/controller/extension/report/customer_search.php b/upload/admin/controller/extension/report/customer_search.php
index 89f33d81d34..5d7cceee174 100644
--- a/upload/admin/controller/extension/report/customer_search.php
+++ b/upload/admin/controller/extension/report/customer_search.php
@@ -1,5 +1,7 @@
 <?php
 class ControllerExtensionReportCustomerSearch extends Controller {
+	private $error = array();
+
 	public function index() {
 		$this->load->language('extension/report/customer_search');
 
diff --git a/upload/admin/controller/extension/report/customer_transaction.php b/upload/admin/controller/extension/report/customer_transaction.php
index 09b476c00eb..cb6ce81c524 100644
--- a/upload/admin/controller/extension/report/customer_transaction.php
+++ b/upload/admin/controller/extension/report/customer_transaction.php
@@ -1,5 +1,7 @@
 <?php
 class ControllerExtensionReportCustomerTransaction extends Controller {
+	private $error = array();
+
 	public function index() {
 		$this->load->language('extension/report/customer_transaction');
 
diff --git a/upload/admin/controller/extension/report/marketing.php b/upload/admin/controller/extension/report/marketing.php
index 0546a17b2d6..360f710784e 100644
--- a/upload/admin/controller/extension/report/marketing.php
+++ b/upload/admin/controller/extension/report/marketing.php
@@ -1,5 +1,7 @@
 <?php
 class ControllerExtensionReportMarketing extends Controller {
+	private $error = array();
+
 	public function index() {
 		$this->load->language('extension/report/marketing');
 
diff --git a/upload/admin/controller/extension/report/product_purchased.php b/upload/admin/controller/extension/report/product_purchased.php
index dd1dca08877..de82263311d 100644
--- a/upload/admin/controller/extension/report/product_purchased.php
+++ b/upload/admin/controller/extension/report/product_purchased.php
@@ -1,5 +1,7 @@
 <?php
 class ControllerExtensionReportProductPurchased extends Controller {
+	private $error = array();
+
 	public function index() {
 		$this->load->language('extension/report/product_purchased');
 
diff --git a/upload/admin/controller/extension/report/product_viewed.php b/upload/admin/controller/extension/report/product_viewed.php
index 337386f5646..6e2df56c516 100644
--- a/upload/admin/controller/extension/report/product_viewed.php
+++ b/upload/admin/controller/extension/report/product_viewed.php
@@ -1,5 +1,7 @@
 <?php
 class ControllerExtensionReportProductViewed extends Controller {
+	private $error = array();
+
 	public function index() {
 		$this->load->language('extension/report/product_viewed');
 
diff --git a/upload/admin/controller/extension/report/sale_coupon.php b/upload/admin/controller/extension/report/sale_coupon.php
index 694877c2338..9eef69b4e2f 100644
--- a/upload/admin/controller/extension/report/sale_coupon.php
+++ b/upload/admin/controller/extension/report/sale_coupon.php
@@ -1,5 +1,7 @@
 <?php
 class ControllerExtensionReportSaleCoupon extends Controller {
+	private $error = array();
+
 	public function index() {
 		$this->load->language('extension/report/sale_coupon');
 
diff --git a/upload/admin/controller/extension/report/sale_order.php b/upload/admin/controller/extension/report/sale_order.php
index 7ec99a78c8e..ad6e01155d6 100644
--- a/upload/admin/controller/extension/report/sale_order.php
+++ b/upload/admin/controller/extension/report/sale_order.php
@@ -1,5 +1,7 @@
 <?php
 class ControllerExtensionReportSaleOrder extends Controller {
+	private $error = array();
+
 	public function index() {
 		$this->load->language('extension/report/sale_order');
 
diff --git a/upload/admin/controller/extension/report/sale_return.php b/upload/admin/controller/extension/report/sale_return.php
index 32490782455..3b43c0a0882 100644
--- a/upload/admin/controller/extension/report/sale_return.php
+++ b/upload/admin/controller/extension/report/sale_return.php
@@ -1,5 +1,7 @@
 <?php
 class ControllerExtensionReportSaleReturn extends Controller {
+	private $error = array();
+
 	public function index() {
 		$this->load->language('extension/report/sale_return');
 
diff --git a/upload/admin/controller/extension/report/sale_shipping.php b/upload/admin/controller/extension/report/sale_shipping.php
index e70390a6af9..0ce14c2b96e 100644
--- a/upload/admin/controller/extension/report/sale_shipping.php
+++ b/upload/admin/controller/extension/report/sale_shipping.php
@@ -1,5 +1,7 @@
 <?php
 class ControllerExtensionReportSaleShipping extends Controller {
+	private $error = array();
+
 	public function index() {
 		$this->load->language('extension/report/sale_shipping');
 
diff --git a/upload/admin/controller/extension/report/sale_tax.php b/upload/admin/controller/extension/report/sale_tax.php
index a1dbe051bcc..b70a22eb53a 100644
--- a/upload/admin/controller/extension/report/sale_tax.php
+++ b/upload/admin/controller/extension/report/sale_tax.php
@@ -1,5 +1,7 @@
 <?php
 class ControllerExtensionReportSaleTax extends Controller {
+	private $error = array();
+
 	public function index() {
 		$this->load->language('extension/report/sale_tax');
 
diff --git a/upload/admin/controller/marketplace/modification.php b/upload/admin/controller/marketplace/modification.php
index 5f98622f20e..320c629d7f3 100644
--- a/upload/admin/controller/marketplace/modification.php
+++ b/upload/admin/controller/marketplace/modification.php
@@ -149,7 +149,7 @@ public function refresh($data = array()) {
 				$recovery = array();
 
 				// Set the a recovery of the modification code in case we need to use it if an abort attribute is used.
-				if (isset($modification)) {
+				if ($modification) {
 					$recovery = $modification;
 				}
 
diff --git a/upload/admin/model/extension/payment/sagepay_direct.php b/upload/admin/model/extension/payment/sagepay_direct.php
index c3da2de9b27..7a5258b1e1e 100644
--- a/upload/admin/model/extension/payment/sagepay_direct.php
+++ b/upload/admin/model/extension/payment/sagepay_direct.php
@@ -245,7 +245,7 @@ public function sendCurl($url, $payment_data) {
 		$response_info = explode(chr(10), $response);
 
 		foreach ($response_info as $i => $string) {
-			if (strpos($string, '=') && isset($i)) {
+			if (strpos($string, '=')) {
 				$parts = explode('=', $string, 2);
 				$data['RepeatResponseData_' . $i][trim($parts[0])] = trim($parts[1]);
 			} elseif (strpos($string, '=')) {
diff --git a/upload/admin/model/extension/payment/sagepay_server.php b/upload/admin/model/extension/payment/sagepay_server.php
index e774e179d48..f77c879eab4 100644
--- a/upload/admin/model/extension/payment/sagepay_server.php
+++ b/upload/admin/model/extension/payment/sagepay_server.php
@@ -246,7 +246,7 @@ public function sendCurl($url, $payment_data) {
 		$response_info = explode(chr(10), $response);
 
 		foreach ($response_info as $i => $string) {
-			if (strpos($string, '=') && isset($i)) {
+			if (strpos($string, '=')) {
 				$parts = explode('=', $string, 2);
 				$data['RepeatResponseData_' . $i][trim($parts[0])] = trim($parts[1]);
 			} elseif (strpos($string, '=')) {
diff --git a/upload/catalog/controller/extension/payment/g2apay.php b/upload/catalog/controller/extension/payment/g2apay.php
index 65c7f06247d..ba903085745 100644
--- a/upload/catalog/controller/extension/payment/g2apay.php
+++ b/upload/catalog/controller/extension/payment/g2apay.php
@@ -43,22 +43,20 @@ public function checkout() {
 				$this->load->model('extension/total/' . $result['code']);
 
 				// We have to put the totals in an array so that they pass by reference.
-				$this->{'model_extension_total_' . $result['code']}->getTotal($total_data);
-
-				if (isset($order_data['totals'][$i])) {
-					if (strstr(strtolower($order_data['totals'][$i]['code']), 'total') === false) {
-						$item = new stdClass();
-						$item->sku = $order_data['totals'][$i]['code'];
-						$item->name = $order_data['totals'][$i]['title'];
-						$item->amount = number_format($order_data['totals'][$i]['value'], 2);
-						$item->qty = 1;
-						$item->id = $order_data['totals'][$i]['code'];
-						$item->price = $order_data['totals'][$i]['value'];
-						$item->url = $this->url->link('common/home', '', true);
-						$items[] = $item;
-					}
-
-					$i++;
+				$total_info = $this->{'model_extension_total_' . $result['code']}->getTotal($total_data);
+
+				if ($total_info) {
+					$item = new \stdClass();
+
+					$item->sku = $total_info['totals']['code'];
+					$item->name = $total_info['totals']['title'];
+					$item->amount = number_format($total_info['totals']['value'], 2);
+					$item->qty = 1;
+					$item->id = $total_info['totals']['code'];
+					$item->price = $total_info['totals']['value'];
+					$item->url = $this->url->link('common/home', '', true);
+
+					$items[] = $item;
 				}
 			}
 		}
diff --git a/upload/catalog/controller/mail/order.php b/upload/catalog/controller/mail/order.php
index c7e5a8ea109..b6f8bfcb533 100644
--- a/upload/catalog/controller/mail/order.php
+++ b/upload/catalog/controller/mail/order.php
@@ -36,7 +36,7 @@ public function index(&$route, &$args) {
 			
 			// If order status is not 0 then send update text email
 			if ($order_info['order_status_id'] && $order_status_id && $notify) {
-				$this->edit($order_info, $order_status_id, $comment, $notify);
+				$this->edit($order_info, $order_status_id, $comment);
 			}		
 		}
 	}
diff --git a/upload/catalog/model/extension/payment/opayo.php b/upload/catalog/model/extension/payment/opayo.php
index 0880ed35488..e24fdabe7a6 100644
--- a/upload/catalog/model/extension/payment/opayo.php
+++ b/upload/catalog/model/extension/payment/opayo.php
@@ -394,7 +394,7 @@ private function getRecurringOrder($order_recurring_id) {
 	private function addRecurring($order_id, $description, $data, $reference) {
 		$order_recurring_id = $this->model_checkout_recurring->addRecurring($order_id, $description, $data);
 		$this->model_checkout_recurring->editReference($order_recurring_id, $reference);
-		return order_recurring_id;
+		return $order_recurring_id;
 	}
 	
 	public function editRecurringStatus($order_recurring_id, $status) {
diff --git a/upload/system/library/googleshopping/googleshopping.php b/upload/system/library/googleshopping/googleshopping.php
index 360e0b2bdc0..be2e3ed26ed 100644
--- a/upload/system/library/googleshopping/googleshopping.php
+++ b/upload/system/library/googleshopping/googleshopping.php
@@ -366,7 +366,7 @@ protected function getFeedProducts($page, $language_id, $currency) {
 
                 do {
                     ${'custom_label_' . ($i++)} = trim(strtolower(array_pop($campaigns)));
-                } while (!empty($campaigns));
+                } while ($campaigns);
             }
 
             $mpn = !empty($row['mpn']) ? $row['mpn'] : '';
@@ -664,7 +664,7 @@ public function cron() {
                     $product_reports = $this->getProductReports($chunk);
 
                     if (!empty($product_reports)) {
-                        $this->updateProductReports($product_reports, $this->store_id);
+                        $this->updateProductReports($product_reports);
                         $report_count += count($product_reports);
                     }
                 }