diff --git a/.changeset/three-dodos-admire.md b/.changeset/three-dodos-admire.md
new file mode 100644
index 0000000000..0a58bd5201
--- /dev/null
+++ b/.changeset/three-dodos-admire.md
@@ -0,0 +1,5 @@
+---
+"@medusajs/core-flows": patch
+---
+
+fix(core-flows): Access orderItem.variant safely inside convertDraftOrderWorkflow when containing custom items
diff --git a/integration-tests/http/__tests__/draft-order/admin/draft-order.spec.ts b/integration-tests/http/__tests__/draft-order/admin/draft-order.spec.ts
index 4e419efc4c..bc6fd04c18 100644
--- a/integration-tests/http/__tests__/draft-order/admin/draft-order.spec.ts
+++ b/integration-tests/http/__tests__/draft-order/admin/draft-order.spec.ts
@@ -416,6 +416,102 @@ medusaIntegrationTestRunner({
         expect(response.status).toBe(200)
         expect(response.data.order.status).toBe("pending")
       })
+
+      it("should convert a draft order with a custom item (without variant_id) to an order", async () => {
+        await api.post(
+          `/admin/draft-orders/${testDraftOrder.id}/edit`,
+          {},
+          adminHeaders
+        )
+
+        await api.post(
+          `/admin/draft-orders/${testDraftOrder.id}/edit/items`,
+          {
+            items: [
+              {
+                title: "Custom Item",
+                quantity: 2,
+                unit_price: 1500,
+              },
+            ],
+          },
+          adminHeaders
+        )
+
+        await api.post(
+          `/admin/draft-orders/${testDraftOrder.id}/edit/confirm`,
+          {},
+          adminHeaders
+        )
+
+        const response = await api.post(
+          `/admin/draft-orders/${testDraftOrder.id}/convert-to-order`,
+          {},
+          adminHeaders
+        )
+
+        expect(response.status).toBe(200)
+        expect(response.data.order.status).toBe("pending")
+      })
+
+      it("should convert a draft order with both variant items and custom items to an order", async () => {
+        await api.post(
+          `/admin/draft-orders/${testDraftOrder.id}/edit`,
+          {},
+          adminHeaders
+        )
+
+        await api.post(
+          `/admin/draft-orders/${testDraftOrder.id}/edit/items`,
+          {
+            items: [
+              {
+                variant_id: product.variants.find((v) => v.title === "L shirt")
+                  .id,
+                quantity: 1,
+              },
+              {
+                title: "Custom Item",
+                quantity: 1,
+                unit_price: 2000,
+              },
+            ],
+          },
+          adminHeaders
+        )
+
+        await api.post(
+          `/admin/draft-orders/${testDraftOrder.id}/edit/confirm`,
+          {},
+          adminHeaders
+        )
+
+        let reservations = (await api.get(`/admin/reservations`, adminHeaders))
+          .data.reservations
+
+        expect(reservations.length).toBe(0)
+
+        const response = await api.post(
+          `/admin/draft-orders/${testDraftOrder.id}/convert-to-order`,
+          {},
+          adminHeaders
+        )
+
+        reservations = (await api.get(`/admin/reservations`, adminHeaders)).data
+          .reservations
+
+        expect(reservations).toEqual(
+          expect.arrayContaining([
+            expect.objectContaining({
+              inventory_item_id: inventoryItemLarge.id,
+              quantity: 1,
+            }),
+          ])
+        )
+
+        expect(response.status).toBe(200)
+        expect(response.data.order.status).toBe("pending")
+      })
     })
 
     describe("POST /draft-orders/:id/edit/items/:item_id", () => {
diff --git a/packages/core/core-flows/src/draft-order/workflows/convert-draft-order.ts b/packages/core/core-flows/src/draft-order/workflows/convert-draft-order.ts
index c7334616a2..8170c23b49 100644
--- a/packages/core/core-flows/src/draft-order/workflows/convert-draft-order.ts
+++ b/packages/core/core-flows/src/draft-order/workflows/convert-draft-order.ts
@@ -143,11 +143,13 @@ export const convertDraftOrderWorkflow = createWorkflow(
 
       for (const orderItem of orderItems.items ?? []) {
         items.push({
-          variant_id: orderItem.variant.id,
+          variant_id: orderItem.variant?.id,
           quantity: orderItem.quantity,
           id: orderItem.id,
         })
-        variants.push(orderItem.variant)
+        if (orderItem.variant) {
+          variants.push(orderItem.variant)
+        }
       }
 
       return {