diff --git a/CHANGELOG.md b/CHANGELOG.md
index 155ab75be4..cc5ce444f6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@
 ## Unreleased
 
 - Fixed a PHP error that could occur on Edit Plan pages. ([#3998](https://github.com/craftcms/commerce/issues/3998))
+- Fixed a PHP error that could occur when upgrading to Commerce 5. ([#3933](https://github.com/craftcms/commerce/pull/3933))
 
 ## 5.3.11 - 2025-05-01
 
diff --git a/src/elements/conditions/orders/OrderCurrencyValuesAttributeConditionRule.php b/src/elements/conditions/orders/OrderCurrencyValuesAttributeConditionRule.php
index 8c0ccfb989..6fff3f5ebf 100644
--- a/src/elements/conditions/orders/OrderCurrencyValuesAttributeConditionRule.php
+++ b/src/elements/conditions/orders/OrderCurrencyValuesAttributeConditionRule.php
@@ -65,7 +65,10 @@ public function setCondition(ConditionInterface $condition): void
         } else {
             /** @var Site|StoreBehavior|null $currentSite */
             $currentSite = Craft::$app->getSites()->getCurrentSite();
-            $this->currency = $currentSite?->getStore()->getCurrency();
+
+            if ($currentSite->getBehavior(StoreBehavior::class)) {
+                $this->currency = $currentSite?->getStore()->getCurrency();
+            }
         }
 
         if ($this->currency) {
@@ -80,7 +83,7 @@ protected function field(): FieldInterface
     {
         // Mock a Money field
         $field = new Money();
-        $field->currency = $this->currency?->getCode();
+        $field->currency = $this->currency?->getCode() ?? $field->currency;
 
         return $field;
     }