diff --git a/src/__tests__/pages/api/widgets/customapi.test.js b/src/__tests__/pages/api/widgets/customapi.test.js
index f2ef68617..92afb3a9b 100644
--- a/src/__tests__/pages/api/widgets/customapi.test.js
+++ b/src/__tests__/pages/api/widgets/customapi.test.js
@@ -67,9 +67,8 @@ describe("pages/api/widgets/customapi", () => {
       headers: { "X-Test": "1", Authorization: `Basic ${Buffer.from("u:p").toString("base64")}` },
       body: '{"foo":"bar"}',
     });
-    expect(res.setHeader).toHaveBeenCalledWith("Content-Type", "application/json");
     expect(res.statusCode).toBe(200);
-    expect(res.body.toString()).toBe('{"a":1}');
+    expect(res.body).toEqual({ a: 1 });
   });
 
   it("defaults to GET and passes string bodies through", async () => {
diff --git a/src/pages/api/widgets/customapi.js b/src/pages/api/widgets/customapi.js
index 2d6d4370d..960f097f2 100644
--- a/src/pages/api/widgets/customapi.js
+++ b/src/pages/api/widgets/customapi.js
@@ -31,14 +31,16 @@ export default async function handler(req, res) {
     params.body = typeof options.requestBody === "object" ? JSON.stringify(options.requestBody) : options.requestBody;
   }
 
-  const [status, contentType, data] = await httpProxy(url, params);
+  const [status, , data] = await httpProxy(url, params);
 
   if (status >= 400) {
     logger.debug("HTTP Error %d calling %s//%s%s", status, url.protocol, url.host, url.pathname);
     return res.status(status).json({ error: { message: "HTTP Error", url: sanitizeErrorURL(url) } });
   }
 
-  if (contentType) res.setHeader("Content-Type", contentType);
-
-  return res.status(status).send(data);
+  try {
+    return res.status(status).json(JSON.parse(Buffer.from(data).toString()));
+  } catch {
+    return res.status(500).json({ error: { message: "Invalid JSON", url: sanitizeErrorURL(url) } });
+  }
 }