diff --git a/src/fiat-api/FiatApi.ts b/src/fiat-api/FiatApi.ts
index f4dfc6c..1f4807d 100644
--- a/src/fiat-api/FiatApi.ts
+++ b/src/fiat-api/FiatApi.ts
@@ -281,6 +281,12 @@ export function setCoingeckoApiUrl(url: string) {
     API_URL = url;
 }
 
+const coingeckoExtraHeaders = new Map<string, string>();
+
+export function setCoingeckoApiExtraHeader(name: string, value: string) {
+    coingeckoExtraHeaders.set(name, value);
+}
+
 type VsCurrency = FiatApiSupportedFiatCurrency | FiatApiBridgedFiatCurrency | FiatApiSupportedCryptoCurrency;
 export async function getExchangeRates<C extends FiatApiSupportedCryptoCurrency, V extends VsCurrency>(
     cryptoCurrencies: C[],
@@ -510,13 +516,15 @@ function _findTimestampChunk(
     };
 }
 
-async function _fetch<T>(input: RequestInfo, init?: RequestInit): Promise<T> {
+async function _fetch<T>(input: RequestInfo): Promise<T> {
     let result: T | null = null;
     do {
         let retry = true;
         try {
             // eslint-disable-next-line no-await-in-loop
-            const response = await fetch(input, init); // throws when user is offline
+            const response = await fetch(input, {
+                headers: [...coingeckoExtraHeaders.entries()],
+            }); // throws when user is offline
             if (!response.ok) {
                 if (response.status === 400) {
                     retry = false;
diff --git a/tests/FiatApi.spec.ts b/tests/FiatApi.spec.ts
index c084171..df806ce 100644
--- a/tests/FiatApi.spec.ts
+++ b/tests/FiatApi.spec.ts
@@ -10,12 +10,19 @@ import {
     FiatApiSupportedFiatCurrency,
     getExchangeRates,
     getHistoricExchangeRates,
+    setCoingeckoApiUrl,
+    setCoingeckoApiExtraHeader,
 } from '../src/fiat-api/FiatApi';
 
 // If tests are failing locally, increase the timeout
 const timeout = /* use default timeout of 5000 */ 0;
 // const timeout = 300000;
 
+setCoingeckoApiUrl('https://nq-coingecko-proxy.deno.dev/api/v3');
+if (process.env.COINGECKO_PROXY_AUTHORIZATION_HEADER && process.env.CI_AUTHORIZATION_TOKEN) {
+    setCoingeckoApiExtraHeader(process.env.COINGECKO_PROXY_AUTHORIZATION_HEADER, process.env.CI_AUTHORIZATION_TOKEN);
+}
+
 describe('FiatApi', () => {
     it('can fetch current USD rate for BTC', async () => {
         const rate = await getExchangeRates(