diff --git a/__tests__/github.test.ts b/__tests__/github.test.ts
index 8880152..719ae9f 100644
--- a/__tests__/github.test.ts
+++ b/__tests__/github.test.ts
@@ -130,18 +130,12 @@ describe('printActionsRuntimeTokenACs', () => {
     process.env = originalEnv;
   });
   it('empty', async () => {
-    const warnSpy = jest.spyOn(core, 'warning');
     process.env.ACTIONS_RUNTIME_TOKEN = '';
-    await GitHub.printActionsRuntimeTokenACs();
-    expect(warnSpy).toHaveBeenCalledTimes(1);
-    expect(warnSpy).toHaveBeenCalledWith(`ACTIONS_RUNTIME_TOKEN not set`);
+    await expect(GitHub.printActionsRuntimeTokenACs()).rejects.toThrowError(new Error('ACTIONS_RUNTIME_TOKEN not set'));
   });
   it('malformed', async () => {
-    const warnSpy = jest.spyOn(core, 'warning');
     process.env.ACTIONS_RUNTIME_TOKEN = 'foo';
-    await GitHub.printActionsRuntimeTokenACs();
-    expect(warnSpy).toHaveBeenCalledTimes(1);
-    expect(warnSpy).toHaveBeenCalledWith(`Cannot parse Actions Runtime Token: Invalid token specified: Cannot read properties of undefined (reading 'replace')`);
+    await expect(GitHub.printActionsRuntimeTokenACs()).rejects.toThrowError(new Error("Cannot parse GitHub Actions Runtime Token: Invalid token specified: Cannot read properties of undefined (reading 'replace')"));
   });
   it('refs/heads/master', async () => {
     const infoSpy = jest.spyOn(core, 'info');
diff --git a/src/github.ts b/src/github.ts
index e7e0404..e7b8e1c 100644
--- a/src/github.ts
+++ b/src/github.ts
@@ -59,12 +59,10 @@ export class GitHub {
     try {
       jwt = GitHub.actionsRuntimeToken;
     } catch (e) {
-      core.warning(`Cannot parse Actions Runtime Token: ${e.message}`);
-      return;
+      throw new Error(`Cannot parse GitHub Actions Runtime Token: ${e.message}`);
     }
     if (!jwt) {
-      core.warning(`ACTIONS_RUNTIME_TOKEN not set`);
-      return;
+      throw new Error(`ACTIONS_RUNTIME_TOKEN not set`);
     }
     try {
       <Array<GitHubActionsRuntimeTokenAC>>JSON.parse(`${jwt.ac}`).forEach(ac => {
@@ -85,7 +83,7 @@ export class GitHub {
         core.info(`${ac.Scope}: ${permission}`);
       });
     } catch (e) {
-      core.warning(`Cannot parse Actions Runtime Token Access Controls: ${e.message}`);
+      throw new Error(`Cannot parse GitHub Actions Runtime Token ACs: ${e.message}`);
     }
   }
 }