diff --git a/src/CartItem.php b/src/CartItem.php
index 4e2e328..64e2cf6 100644
--- a/src/CartItem.php
+++ b/src/CartItem.php
@@ -274,7 +274,7 @@ class CartItem implements Arrayable, Jsonable
             return $this->tax * $this->qty;
         }
 
-        if($attribute === 'model') {
+        if($attribute === 'model' && isset($this->associatedModel)) {
             return with(new $this->associatedModel)->find($this->id);
         }