diff --git a/yarn-project/prover-client/src/proving_broker/proving_broker.test.ts b/yarn-project/prover-client/src/proving_broker/proving_broker.test.ts
index 42ce07819f2..e0609ce22dd 100644
--- a/yarn-project/prover-client/src/proving_broker/proving_broker.test.ts
+++ b/yarn-project/prover-client/src/proving_broker/proving_broker.test.ts
@@ -63,6 +63,28 @@ describe.each([
       await broker.stop();
     });
 
+    it('refuses stale jobs', async () => {
+      const id = makeProvingJobId();
+      await broker.enqueueProvingJob({
+        id,
+        epochNumber: 42,
+        type: ProvingRequestType.BASE_PARITY,
+        inputsUri: makeInputsUri(),
+      });
+      expect(await broker.getProvingJobStatus(id)).toEqual({ status: 'in-queue' });
+
+      const id2 = makeProvingJobId();
+      await expect(
+        broker.enqueueProvingJob({
+          id: id2,
+          epochNumber: 1,
+          type: ProvingRequestType.PRIVATE_BASE_ROLLUP,
+          inputsUri: makeInputsUri(),
+        }),
+      ).rejects.toThrow();
+      await assertJobStatus(id2, 'not-found');
+    });
+
     it('enqueues jobs', async () => {
       const id = makeProvingJobId();
       await broker.enqueueProvingJob({
@@ -210,15 +232,7 @@ describe.each([
         inputsUri: makeInputsUri(),
       };
 
-      const provingJob3: ProvingJob = {
-        id: makeProvingJobId(),
-        type: ProvingRequestType.BASE_PARITY,
-        epochNumber: 3,
-        inputsUri: makeInputsUri(),
-      };
-
       await broker.enqueueProvingJob(provingJob2);
-      await broker.enqueueProvingJob(provingJob3);
       await broker.enqueueProvingJob(provingJob1);
 
       await getAndAssertNextJobId(provingJob1.id, ProvingRequestType.BASE_PARITY);
diff --git a/yarn-project/prover-client/src/proving_broker/proving_broker.ts b/yarn-project/prover-client/src/proving_broker/proving_broker.ts
index 4086c5b3803..6edf6c824e2 100644
--- a/yarn-project/prover-client/src/proving_broker/proving_broker.ts
+++ b/yarn-project/prover-client/src/proving_broker/proving_broker.ts
@@ -181,6 +181,13 @@ export class ProvingBroker implements ProvingJobProducer, ProvingJobConsumer, Tr
       return;
     }
 
+    if (this.isJobStale(job)) {
+      this.logger.warn(`Tried enqueueing stale proving job id=${job.id} epochNumber=${job.epochNumber}`, {
+        provingJobId: job.id,
+      });
+      throw new Error(`Epoch too old: job epoch ${job.epochNumber}, current epoch: ${this.epochHeight}`);
+    }
+
     this.logger.info(`New proving job id=${job.id} epochNumber=${job.epochNumber}`, { provingJobId: job.id });
     try {
       // do this first so it acts as a "lock". If this job is enqueued again while we're saving it the if at the top will catch it.