diff --git a/runners/agent-runner/test/reviewer-runtime.test.ts b/runners/agent-runner/test/reviewer-runtime.test.ts
index 6f968af..3bfbde7 100644
--- a/runners/agent-runner/test/reviewer-runtime.test.ts
+++ b/runners/agent-runner/test/reviewer-runtime.test.ts
@@ -138,8 +138,10 @@ describe('claude reviewer runtime guard', () => {
       'best-effort',
     );
 
-    expect(sandbox).toBeDefined();
-    expect(sandbox?.failIfUnavailable).toBe(false);
+    if (!sandbox) {
+      throw new Error('expected sandbox settings');
+    }
+    expect(sandbox.failIfUnavailable).toBe(false);
   });
 
   it('keeps non-linux reviewers in best-effort sandbox mode', () => {
@@ -153,8 +155,10 @@ describe('claude reviewer runtime guard', () => {
       'best-effort',
     );
 
-    expect(sandbox).toBeDefined();
-    expect(sandbox?.failIfUnavailable).toBe(false);
+    if (!sandbox) {
+      throw new Error('expected sandbox settings');
+    }
+    expect(sandbox.failIfUnavailable).toBe(false);
   });
 
   it('flags mutating shell commands', () => {