diff --git a/src/core/batch-api.ts b/src/core/batch-api.ts
index 98f1a82..586a72c 100644
--- a/src/core/batch-api.ts
+++ b/src/core/batch-api.ts
@@ -76,7 +76,7 @@ interface ProblemJson {
 }
 
 /** Terminal run states — a run stops progressing once it reaches one of these. */
-export const TERMINAL_STATUSES: ReadonlySet<string> = new Set(["completed", "stopped", "deleted"]);
+export const TERMINAL_STATUSES: ReadonlySet<string> = new Set(["completed", "stopped", "failed", "deleted"]);
 
 interface RequestOpts {
   apiKey: string;
diff --git a/tests/batch-api.test.ts b/tests/batch-api.test.ts
index 74e1eca..0b69650 100644
--- a/tests/batch-api.test.ts
+++ b/tests/batch-api.test.ts
@@ -203,3 +203,19 @@ test("waitForJob polls until a terminal status", async () => {
   assert.equal(job.latest_run.status, "completed");
   assert.equal(i, 3);
 });
+
+test("waitForJob treats failed as terminal", async () => {
+  const statuses = ["running", "failed"];
+  let i = 0;
+  const impl = (async () => {
+    const status = statuses[Math.min(i++, statuses.length - 1)]!;
+    return new Response(
+      JSON.stringify({ job_id: "j", latest_run: { status, failure_reason: "insufficient_credits", stats: { total: 1, completed: 0, successful: 0, failed: 0 } } }),
+      { status: 200, headers: { "content-type": "application/json" } },
+    );
+  }) as unknown as typeof fetch;
+
+  const job = await waitForJob("j", { apiKey: "k", fetchImpl: impl, sleepImpl: async () => {} });
+  assert.equal(job.latest_run.status, "failed");
+  assert.equal(i, 2);
+});