diff --git a/packages/medusa/src/services/__tests__/totals.js b/packages/medusa/src/services/__tests__/totals.js
index 1260081d50258..0b524efc54710 100644
--- a/packages/medusa/src/services/__tests__/totals.js
+++ b/packages/medusa/src/services/__tests__/totals.js
@@ -708,8 +708,6 @@ describe("TotalsService", () => {
   })
 
   describe("getShippingTotal", () => {
-    let res
-
     const getTaxLinesMock = jest.fn(() =>
       Promise.resolve([
         { shipping_method_id: IdMap.getId("expensiveShipping") },
@@ -749,9 +747,9 @@ describe("TotalsService", () => {
           },
         ],
       }
-      res = await totalsService.getShippingTotal(order)
+      const total = await totalsService.getShippingTotal(order)
 
-      expect(res).toEqual(100)
+      expect(total).toEqual(100)
     })
   })
 
@@ -1011,6 +1009,17 @@ describe("TotalsService", () => {
   })
 
   describe("[MEDUSA_FF_TAX_INCLUSIVE_PRICING] getShippingTotal ", () => {
+    const shippingMethodData = {
+      id: IdMap.getId("expensiveShipping"),
+      name: "Expensive Shipping",
+      price: 120,
+      tax_lines: [{ shipping_method_id: IdMap.getId("expensiveShipping") }],
+      provider_id: "default_provider",
+      profile_id: IdMap.getId("default"),
+      data: {
+        extra: "hi",
+      },
+    }
     const calculateMock = jest.fn(() => Promise.resolve(20))
     const totalsService = new TotalsService({
       ...container,
@@ -1026,41 +1035,56 @@ describe("TotalsService", () => {
       jest.clearAllMocks()
     })
 
-    it("calculates total", async () => {
+    it("calculates total with tax lines and being tax inclusive", async () => {
       const order = {
-        tax_rate: null,
-        items: [
+        object: "order",
+        shipping_methods: [
           {
-            unit_price: 20,
-            quantity: 2,
+            ...shippingMethodData,
+            includes_tax: true,
           },
+        ],
+      }
+
+      const total = await totalsService.getShippingTotal(order)
+
+      expect(total).toEqual(100)
+    })
+
+    it("calculates total with tax lines and not being tax inclusive", async () => {
+      const order = {
+        object: "order",
+        shipping_methods: [
           {
-            unit_price: 25,
-            quantity: 2,
-            includes_tax: true,
+            ...shippingMethodData,
+            price: 100,
+            includes_tax: false,
           },
         ],
+      }
+
+      const total = await totalsService.getShippingTotal(order)
+
+      expect(total).toEqual(100)
+    })
+
+    it("calculates total with the old system and not being tax inclusive", async () => {
+      const order = {
+        object: "order",
+        tax_rate: 20,
         shipping_methods: [
           {
-            id: IdMap.getId("expensiveShipping"),
-            name: "Expensive Shipping",
-            price: 120,
-            includes_tax: true,
-            tax_lines: [
-              { shipping_method_id: IdMap.getId("expensiveShipping") },
-            ],
-            provider_id: "default_provider",
-            profile_id: IdMap.getId("default"),
-            data: {
-              extra: "hi",
-            },
+            ...shippingMethodData,
+            price: 100,
+            includes_tax: false,
+            tax_lines: [],
           },
         ],
       }
 
-      const res = await totalsService.getShippingTotal(order)
+      const total = await totalsService.getShippingTotal(order)
 
-      expect(res).toEqual(100)
+      expect(total).toEqual(100)
     })
   })
 })
diff --git a/packages/medusa/src/services/totals.ts b/packages/medusa/src/services/totals.ts
index a271e10a6d990..59dc48722d5c4 100644
--- a/packages/medusa/src/services/totals.ts
+++ b/packages/medusa/src/services/totals.ts
@@ -210,7 +210,7 @@ class TotalsService extends TransactionBaseService {
     }
 
     if (opts.include_tax) {
-      if (isOrder(cartOrOrder) && cartOrOrder.tax_rate !== null) {
+      if (isOrder(cartOrOrder) && cartOrOrder.tax_rate != null) {
         totals.original_tax_total = Math.round(
           totals.price * (cartOrOrder.tax_rate / 100)
         )
@@ -825,10 +825,10 @@ class TotalsService extends TransactionBaseService {
 
     // Tax Information
     if (options.include_tax) {
-      // When we have an order with a null'ed tax rate we know that it is an
+      // When we have an order with a nulled or undefined tax rate we know that it is an
       // order from the old tax system. The following is a backward compat
       // calculation.
-      if (isOrder(cartOrOrder) && cartOrOrder.tax_rate !== null) {
+      if (isOrder(cartOrOrder) && cartOrOrder.tax_rate != null) {
         const taxRate = cartOrOrder.tax_rate / 100
 
         const includesTax =