diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7f50ed36e1..52e8b5b059 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@
 ## Unreleased
 
 - Fixed an SQL error that occurred when duplicating variants. ([#3727](https://github.com/craftcms/commerce/issues/3727))
+- Fixed a PHP error that could occur when completing an order. ([#3733](https://github.com/craftcms/commerce/issues/3733))
 
 ## 5.2.0 - 2024-10-16
 
diff --git a/src/services/LineItems.php b/src/services/LineItems.php
index c8a65c7142..e7627fde24 100644
--- a/src/services/LineItems.php
+++ b/src/services/LineItems.php
@@ -520,7 +520,7 @@ public function eagerLoadLineItemsForOrders(array $orders): array
     public function orderCompleteHandler(LineItem $lineItem, Order $order): void
     {
         // Called the after order complete method for the purchasable if there is one
-        if ($lineItem->getPurchasable()) {
+        if ($lineItem->type === LineItemType::Purchasable && $lineItem->getPurchasable()) {
             $lineItem->getPurchasable()->afterOrderComplete($order, $lineItem);
         }