diff --git a/src/ApiClient.ts b/src/ApiClient.ts
index f56ae4d34..4766f7388 100644
--- a/src/ApiClient.ts
+++ b/src/ApiClient.ts
@@ -109,7 +109,7 @@ export default class ApiClient {
           {
             pathPrefix: this.pathPrefix,
             mode: 'cors',
-            headers: { Authorization: `Bearer ${authToken}` },
+            headers: new Headers({ Authorization: `Bearer ${authToken}` }),
           },
         ],
         this.maxRetries,
diff --git a/test/ApiClient.test.ts b/test/ApiClient.test.ts
index 82984b8b7..ab3238aa1 100644
--- a/test/ApiClient.test.ts
+++ b/test/ApiClient.test.ts
@@ -154,9 +154,7 @@ describe('Publish', () => {
     expect(publishMock).toHaveBeenCalledWith(expectedRequest, {
       pathPrefix: PATH_PREFIX,
       mode: 'cors',
-      headers: {
-        Authorization: `Bearer ${AUTH_TOKEN}`,
-      },
+      headers: new Headers({ Authorization: `Bearer ${AUTH_TOKEN}` }),
     })
   })