diff --git a/.changeset/dull-donkeys-ring.md b/.changeset/dull-donkeys-ring.md
new file mode 100644
index 0000000000000..e41836766e03b
--- /dev/null
+++ b/.changeset/dull-donkeys-ring.md
@@ -0,0 +1,5 @@
+---
+"@medusajs/core-flows": patch
+---
+
+(fix) Variants changed from managed inventory to unmanaged are now fulfillable
diff --git a/packages/core/core-flows/src/order/workflows/mark-order-fulfillment-as-delivered.ts b/packages/core/core-flows/src/order/workflows/mark-order-fulfillment-as-delivered.ts
index baad36425ae9f..83d3d477b10dd 100644
--- a/packages/core/core-flows/src/order/workflows/mark-order-fulfillment-as-delivered.ts
+++ b/packages/core/core-flows/src/order/workflows/mark-order-fulfillment-as-delivered.ts
@@ -168,8 +168,8 @@ function prepareRegisterDeliveryData({
         const iitem = iitems.find(
           (i) => i.inventory.id === fitem.inventory_item_id
         )
-
-        quantity = MathBN.div(quantity, iitem!.required_quantity)
+        if(iitem)
+          quantity = MathBN.div(quantity, iitem.required_quantity)
       }
 
       return {