diff --git a/.psalm/wcs.php b/.psalm/wcs.php
index 873fd4d50..a35088c88 100644
--- a/.psalm/wcs.php
+++ b/.psalm/wcs.php
@@ -2084,3 +2084,12 @@ function wcs_find_matching_line_item($order, $subscription_item, $match_type = '
 function wcs_order_contains_product($order, $product)
 {
 }
+
+/**
+ * Get page ID for a specific WC resource.
+ *
+ * @param string $for Name of the resource.
+ *
+ * @return string Page ID. Empty string if resource not found.
+ */
+function wc_get_page_screen_id( $for ) {}
diff --git a/modules/ppcp-subscription/src/DeactivatePlanEndpoint.php b/modules/ppcp-subscription/src/DeactivatePlanEndpoint.php
index c2d490e81..fe10c0638 100644
--- a/modules/ppcp-subscription/src/DeactivatePlanEndpoint.php
+++ b/modules/ppcp-subscription/src/DeactivatePlanEndpoint.php
@@ -10,6 +10,7 @@ declare( strict_types=1 );
 namespace WooCommerce\PayPalCommerce\Subscription;
 
 use Exception;
+use WC_Product;
 use WC_Subscriptions_Product;
 use WooCommerce\PayPalCommerce\ApiClient\Endpoint\BillingPlans;
 use WooCommerce\PayPalCommerce\Button\Endpoint\RequestData;
@@ -68,7 +69,7 @@ class DeactivatePlanEndpoint {
 			$product_id = $data['product_id'] ?? '';
 			if ( $product_id ) {
 				$product = wc_get_product( $product_id );
-				if ( WC_Subscriptions_Product::is_subscription( $product ) ) {
+				if ( is_a( $product, WC_Product::class ) && WC_Subscriptions_Product::is_subscription( $product ) ) {
 					$product->delete_meta_data( '_ppcp_enable_subscription_product' );
 					$product->delete_meta_data( '_ppcp_subscription_plan_name' );
 					$product->delete_meta_data( 'ppcp_subscription_product' );
diff --git a/modules/ppcp-subscription/src/SubscriptionModule.php b/modules/ppcp-subscription/src/SubscriptionModule.php
index 9d690129a..7c6d71a7c 100644
--- a/modules/ppcp-subscription/src/SubscriptionModule.php
+++ b/modules/ppcp-subscription/src/SubscriptionModule.php
@@ -160,7 +160,15 @@ class SubscriptionModule implements ModuleInterface {
 
 		add_action(
 			'admin_enqueue_scripts',
+			/**
+			 * Param types removed to avoid third-party issues.
+			 *
+			 * @psalm-suppress MissingClosureParamType
+			 */
 			function( $hook ) use ( $c ) {
+				if ( ! is_string( $hook ) ) {
+					return;
+				}
 				$settings          = $c->get( 'wcgateway.settings' );
 				$subscription_mode = $settings->has( 'subscriptions_mode' ) ? $settings->get( 'subscriptions_mode' ) : '';
 				if ( $hook !== 'post.php' || $subscription_mode !== 'subscriptions_api' ) {
@@ -183,7 +191,7 @@ class SubscriptionModule implements ModuleInterface {
 					true
 				);
 
-				$plan    = $product->get_meta( 'ppcp_subscription_plan' ) ?? null;
+				$plan    = $product->get_meta( 'ppcp_subscription_plan' ) ?? array();
 				$plan_id = $plan['id'] ?? '';
 				wp_localize_script(
 					'ppcp-paypal-subscription',