diff --git a/lib/entry-points.js b/lib/entry-points.js
index 19f324e0f..681f56b89 100644
--- a/lib/entry-points.js
+++ b/lib/entry-points.js
@@ -170765,9 +170765,13 @@ function getApiClientWithExternalAuth(apiDetails, proxy) {
   return createApiClientWithDetails(apiDetails, { allowExternal: true, proxy });
 }
 function getAuthorizationHeaderFor(logger2, apiDetails, url2) {
+  const token = apiDetails.auth?.trim();
+  if (token === void 0 || token === "") {
+    return void 0;
+  }
   if (url2.startsWith(`${apiDetails.url}/`) || apiDetails.apiURL && url2.startsWith(`${apiDetails.apiURL}/`)) {
     logger2.debug(`Providing an authorization token.`);
-    return `token ${apiDetails.auth}`;
+    return `token ${token}`;
   }
   logger2.debug(`Not using an authorization token.`);
   return void 0;
diff --git a/src/api-client.test.ts b/src/api-client.test.ts
index 12fe81985..1a37425e4 100644
--- a/src/api-client.test.ts
+++ b/src/api-client.test.ts
@@ -8,7 +8,14 @@ import * as actionsUtil from "./actions-util";
 import * as api from "./api-client";
 import { DO_NOT_RETRY_STATUSES } from "./api-client";
 import { ActionsEnvVars, RegistryProxyVars } from "./environment";
-import { callee, getTestEnv, setupTests } from "./testing-utils";
+import { GITHUB_DOTCOM_API_URL, GITHUB_DOTCOM_URL } from "./github";
+import {
+  callee,
+  getTestEnv,
+  RecordingLogger,
+  SAMPLE_DOTCOM_API_DETAILS,
+  setupTests,
+} from "./testing-utils";
 import * as util from "./util";
 
 setupTests(test);
@@ -284,3 +291,74 @@ test("makeProxyRequestOptions - returns fetch with custom proxy", async (t) => {
     githubUtils.defaults.request,
   );
 });
+
+test("getAuthorizationHeaderFor - returns undefined if there's no token", (t) => {
+  const logger = new RecordingLogger();
+
+  t.is(
+    api.getAuthorizationHeaderFor(
+      logger,
+      { ...SAMPLE_DOTCOM_API_DETAILS, auth: undefined },
+      `${GITHUB_DOTCOM_URL}/github`,
+    ),
+    undefined,
+  );
+  t.is(
+    api.getAuthorizationHeaderFor(
+      logger,
+      { ...SAMPLE_DOTCOM_API_DETAILS, auth: "" },
+      `${GITHUB_DOTCOM_URL}/github`,
+    ),
+    undefined,
+  );
+  t.is(
+    api.getAuthorizationHeaderFor(
+      logger,
+      { ...SAMPLE_DOTCOM_API_DETAILS, auth: "    " },
+      `${GITHUB_DOTCOM_URL}/github`,
+    ),
+    undefined,
+  );
+});
+
+test("getAuthorizationHeaderFor - returns header value with token if url is allowed", (t) => {
+  const logger = new RecordingLogger();
+
+  t.is(
+    api.getAuthorizationHeaderFor(
+      logger,
+      SAMPLE_DOTCOM_API_DETAILS,
+      `${GITHUB_DOTCOM_URL}/github`,
+    ),
+    `token ${SAMPLE_DOTCOM_API_DETAILS.auth}`,
+  );
+  t.is(
+    api.getAuthorizationHeaderFor(
+      logger,
+      SAMPLE_DOTCOM_API_DETAILS,
+      `${GITHUB_DOTCOM_API_URL}/github`,
+    ),
+    `token ${SAMPLE_DOTCOM_API_DETAILS.auth}`,
+  );
+});
+
+test("getAuthorizationHeaderFor - returns undefined if url is not allowed", (t) => {
+  const logger = new RecordingLogger();
+
+  t.is(
+    api.getAuthorizationHeaderFor(
+      logger,
+      SAMPLE_DOTCOM_API_DETAILS,
+      `https://localhost/github`,
+    ),
+    undefined,
+  );
+  t.is(
+    api.getAuthorizationHeaderFor(
+      logger,
+      SAMPLE_DOTCOM_API_DETAILS,
+      `https://api.localhost/github`,
+    ),
+    undefined,
+  );
+});
diff --git a/src/api-client.ts b/src/api-client.ts
index 4d0a99920..b75aacbb7 100644
--- a/src/api-client.ts
+++ b/src/api-client.ts
@@ -195,6 +195,12 @@ export function getAuthorizationHeaderFor(
   apiDetails: GitHubApiDetails,
   url: string,
 ): string | undefined {
+  // We don't have to check the `url` if we don't have a token to begin with.
+  const token = apiDetails.auth?.trim();
+  if (token === undefined || token === "") {
+    return undefined;
+  }
+
   // We only want to provide an authorization header if we are downloading
   // from the same GitHub instance the Action is running on.
   // This avoids leaking Enterprise tokens to dotcom.
@@ -203,7 +209,7 @@ export function getAuthorizationHeaderFor(
     (apiDetails.apiURL && url.startsWith(`${apiDetails.apiURL}/`))
   ) {
     logger.debug(`Providing an authorization token.`);
-    return `token ${apiDetails.auth}`;
+    return `token ${token}`;
   }
 
   logger.debug(`Not using an authorization token.`);