diff --git a/package.json b/package.json
index 25152ab..5ae4f76 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@acid-tango/arcus-js",
-  "version": "0.1.0",
+  "version": "0.1.1",
   "description": "",
   "author": "",
   "license": "MIT",
diff --git a/src/Arcus.spec.ts b/src/Arcus.spec.ts
index 651c4d3..8bbd20f 100644
--- a/src/Arcus.spec.ts
+++ b/src/Arcus.spec.ts
@@ -1,6 +1,7 @@
 import { NETFLIX, TELCEL, TOTALPLAY, TRANSACTION } from '../test/fixtures/fixtures';
 import { Arcus } from './Arcus';
 import { ArcusBiller } from './typings/ArcusBiller';
+import { ArcusErrorCode } from './typings/ArcusErrorCode';
 
 const billerWithName = (name: string) => (utility: ArcusBiller) => utility.name === name;
 
@@ -133,5 +134,20 @@ describe('Arcus', () => {
 
   it.todo('deleteBill');
 
-  it.todo('singlePay');
+  describe('singlePay', () => {
+    // At the time of this test, this biller was failing because a 504, now it's working
+    it.skip('does not fail when buying a top up', async () => {
+      const error = await arcus
+        .singlePay({
+          billerId: 13597,
+          accountNumber: '4545454545',
+          currency: 'MXN',
+          amount: 10,
+          externalId: 'db8bf3b9-6db5-410f-ac5f-e0967eac5ff9',
+        })
+        .catch((error) => error);
+
+      expect(error.code).toEqual(ArcusErrorCode.UNEXPECTED_ERROR);
+    });
+  });
 });
diff --git a/src/Arcus.ts b/src/Arcus.ts
index 76e636c..0698b86 100644
--- a/src/Arcus.ts
+++ b/src/Arcus.ts
@@ -43,6 +43,19 @@ export class Arcus {
   }
 
   private static async dealWithErrors(response: Response) {
+    /**
+     * If status is greater than 500, Arcus is returning and HTML response, so we can't treat the
+     * body as JSON
+     */
+    if (response.status >= 500) {
+      const text = await response.text();
+
+      throw new ArcusError(
+        ArcusErrorCode.UNEXPECTED_ERROR,
+        text || `Unknown error from Arcus: ${response.status}`,
+      );
+    }
+
     if (response.status >= 400) {
       const body: ArcusErrorResponse | undefined = await response.json();